uk: Математика, природничі науки

description: For the moduli of derived category objects or the partial desingularizations of the moduli stack of semistable sheaves on Calabi-Yau 3-folds, there are no perfect obstruction theories but only semi-perfect obstruction theories. While a semi-perfect obstruction theory is sufficient for the construction of virtual cycles in Chow groups, it seems insufficient for virtual structure sheaves. In this talk, I will introduce the notion of an almost perfect obstruction theory, which lies in between a semi-perfect obstruction theory and an honest perfect obstruction theory. I will show that an almost perfect obstruction theory enables us to construct the virtual structure sheaf and hence K-theoretic virtual invariants. Examples of DM stacks with almost perfect obstruction theories include the Inaba-Lieblich moduli spaces of simple gluable perfect complexes and the partial desingularizations of moduli stacks of semistable sheaves on Calabi-Yau 3-folds. We thus obtain K-theoretic Donaldson-Thomas invariants of derived category objects and K-theoretic generalized Donaldson-Thomas invariants. Based on a joint work with Michail Savvas.

uk: вхід без авторизації


The punctured logarithmic maps

Qile Chen

type: Person

cs: Matematika

de: Mathematik

fi: matematiikka

uk: Математика

en: Mathematics

fr: Mathématiques

da: Matematik

es: Matemáticas

nl: Wiskunde

de: Mathematik, Naturwissenschaften

uk: Математика, природничі науки

en: Mathematics, Natural Sciences

description: Logarithmic Gromov-Witten theory virtually counts the number of holomorphic curves with prescribed tangency condition along boundary divisors. In this talk I will introduce a variant of logarithmic maps called the punctured logarithmic maps. They naturally appear in a generalization of the gluing formulas of Li-Ruan and Jun Li. The punctured invariants play the role of relative invariants in these classical gluing formulas. They extend logarithmic Gromov-Witten theory by allowing negative tangency conditions with boundary divisors. This talk is based on a joint work with Dan Abramovich, Mark Gross and Bernd Siebert.

TIB AV-Portal

type: Service

type: WebContent

type: MediaObject

@language: en

cs: přihlášení není vyžadováno

de: keine Anmeldung erforderlich

uk: вхід без авторизації

en: no login required

nl: geen login vereist

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery

type: Organization

cs: Video

de: Video

fi: Video

uk: Відео

en: Video

fr: Vidéo

da: Video

nl: Video

es: Video


uk: Математика, природничі науки

description: The Hilbert scheme parameterizing n points on a K3 surface X is a holomorphic symplectic manifold with rich properties. In the 90s it was discovered that the generating function for the Euler characteristics of the Hilbert schemes is related to both modular forms and the enumerative geometry of rational curves on X. We show how this beautiful story generalizes to K3 surfaces with a symplectic action of a group G. Namely, the Euler characteristics of the "G-fixed Hilbert schemes” parametrizing G-invariant collections of points on X are related to modular forms of level |G| and the enumerative geometry of rational curves on the stack quotient [X/G] . These ideas lead to some beautiful new product formulas for theta functions associated to root lattices. The picture also generalizes to refinements of the Euler characteristic such as χy genus and elliptic genus leading to connections with Jacobi forms and Siegel modular forms.

uk: вхід без авторизації

name: K3 surfaces with symplectic group actions, enumerative geometry, and modular forms


uk: Математика, природничі науки

description: Gromov-Witten invariants of Calabi-Yau one-folds (including elliptic curves and elliptic orbifold curves) are quasimodular forms. This can be proved using tautological relations and some ordinary differential equations in the theory of quasimodular forms, with minimal calculations. Such a method is also applicable to the Fan-Jarvis-Ruan-Witten theory of simple elliptic singularities. This allow us to prove the LG/CY correspondence for all CY one-folds using Cayley transformation of quasimodular forms, where GW/FJRW invariants are coefficients of Fourier/Taylor expansions of the same quasimodular forms. This talk is based on joint work with Jie Zhou, and Jun Li, Jie Zhou.

uk: вхід без авторизації

name: LG/CY correspondence for one-folds via modularity


uk: Математика, природничі науки

uk: вхід без авторизації

name: DT/PT correspondence for Calabi-Yau 4-folds


uk: Математика, природничі науки

description: For a large class of GIT quotients X=W//G, Ciocan-Fontanine-Kim-Maulik and many others have developed the theory of epsilon-stable quasimaps. The conjectured wall-crossing formula of cohomological epsilon-stable quasimap invariants for all targets in all genera has been recently proved by Yang Zhou. In this talk, we will introduce permutation-equivariant K-theoretic epsilon-stable quasimap invariants with level structure and prove their wall-crossing formulae for all targets in all genera. In physics literature, these invariants are related to the 3dN=2 supersymmetric gauge theories studied by Jockers-Mayr, and the wall-crossing formulae can be interpreted as relations between invariants in the UV and the IR phases of the 3d gauge theory. It is based on joint work in progress with Yang Zhou.

uk: вхід без авторизації

name: K-theoretic quasimap wall-crossing for GIT quotients


uk: Математика, природничі науки

description: A driving question in Gromov-Witten theory is to relate the invariants of a complete intersection to the invariants of the ambient variety. In genus-zero this can often be done with a ``twisted theory,'' but this fails in higher genus. Several years ago, Chang-Li presented the moduli space of p-fields as a piece of the solution to the higher-genus problem, constructing the virtual cycle on the space of maps to the quintic 3-fold as a cosection localized virtual cycle on a larger moduli space (the space of p-fields). Their result is analogous to the classical statement that the Euler class of a vector bundle is the class of the zero locus of a generic section. I will discuss work joint with Qile Chen and Felix Janda where we extend Chang-Li's result to a more general setting, a setting that includes standard Gromov-Witten theory of smooth orbifold targets and quasimap theory of GIT targets. This work is joint with Qile Chen and Felix Janda.

uk: вхід без авторизації

name: Virtual Cycle on the Moduli Space of Maps to a Complete Intersection.


uk: Математика, природничі науки

description: I will present a moduli space of "logarithmic R-maps" (joint work with Q. Chen and Y. Ruan), which together with its virtual cycles are the key ingredient toward an approach to proving many "mirror" conjectures about higher genus Gromov-Witten invariants of quintic threefolds (joint work with S. Guo and Y. Ruan).

uk: вхід без авторизації

name: The logarithmic gauged linear sigma model


Stable pairs with a twist

uk: Математика, природничі науки

description: The moduli of stable log varieties or stable pairs (X,D) are the higher dimensional analogue of the compactified moduli of stable pointed curves. The existence of a proper moduli space has been established thanks to the last several decades of advancements in the minimal model program. However, the notion of a family of stable pairs remains quite subtle, and in particular a deformation-obstruction theory for these moduli is not known. When the boundary divisor D is empty, Abramovich and Hassett gave an approach to stable varieties that replaces X with an associated orbifold. They show in this setting that the quite subtle notion of family of stable varieties becomes simply a flat family of the associated orbifolds. We extend this approach to the case where there is a nonempty but reduced boundary divisor D with the hopes of producing a deformation-obstruction theory for these moduli spaces. As an application we show that this approach leads to functorial gluing morphisms on the moduli spaces, generalizing the clutching and gluing morphisms that describe the boundary strata of the moduli of curves. This is joint work with G. Inchiostro.

uk: вхід без авторизації


Counting sheaves on Calabi-Yau 4-folds

uk: Математика, природничі науки

description: We define a localised Euler class for isotropic sections, and isotropic cones, in SO(N) bundles. We use this to give an algebraic definition of Borisov-Joyce's sheaf counting invariants on Calabi-Yau 4-folds. When a torus acts, we prove a localisation result. This talk is based on the joint work with R. P. Thomas.

uk: вхід без авторизації


uk: Математика, природничі науки

description: We will show by "generic smoothness" that the big quantum cohomology ring of isotropic Grassmannians IG(2,2n) is generically semisimple but the small quantum cohomology ring is not. That non-semisimplicity leads to a decomposition of the small quantum cohomology ring that relates to a certain decomposition of the derived category of IG(2,2n) in a so-called Lefschetz exceptional collection. This is based on joint work with A. Mellit, A. Kuznetsov, N. Perrin and M. Smirnov.

uk: вхід без авторизації

name: Quantum cohomology for isotropic Grassmannians and Lefschetz exceptional collections


uk: Математика, природничі науки

description: We will start with an expository overview of various approaches and equivalences to the Connes Embedding Problem and then focus on three of Slofstra’s contributions.

uk: вхід без авторизації

name: Slofstra’s Contributions to the Connes Embedding Problem


uk: Математика, природничі науки

description: Tsirelson's problem asks a question about modeling locality in quantum mechanics; roughly speaking, whether the tensor product and commuting models for specifying bipartite correlations are equivalent. Ozawa showed that Tsirelson's problem is equivalent to Connes' Embedding Problem In the talk I will start from Tsirelson's problem and outline a possible approach to its resolution that goes through the theory of nonlocal games in quantum information and interactive proofs in complexity theory. The talk will be introductory and largely based on the work of others, including Navascues, Pironio and Acin, and Doherty, Liang, Toner, and Wehner. I will not assume any background in complexity theory.

uk: вхід без авторизації

name: A complexity-theoretic approach to disproving Connes' Embedding Problem


uk: Математика, природничі науки

uk: вхід без авторизації

name: Compression of non-local games via self-testing


uk: Математика, природничі науки

description: How much, and what sort of entanglement is needed to win a non-local game? In many ways this is the central question in the study of non-local games, and as we've seen in the previous talks, a full understanding of this question could resolve such conundrums as Tsirelson's problem, the complexity of MIP*, and Connes' embedding conjecture. One approach to this question which has proved fruitful is to design *self-tests*: games for which players who wish to play almost optimally must share a quantum state that is close to a specific entangled state. In this talk I'll present a self-test for high-dimensional maximally entangled states that is *efficient* and *robust*: to test n qubits of entanglement requires a game of poly(n) size, and the test gives guarantees even for strategies that are constant far from optimal. These properties are motivated by the complexity-theoretic goal of showing that the entangled value of a nonlocal game is strictly harder to approximate than the classical value. Based on joint work with Thomas Vidick.

uk: вхід без авторизації

name: You must have n qubits or more to win: efficient self-tests for high-dimensional entanglement


uk: Математика, природничі науки

description: One of the most confounding open problems in quantum computing is whether we can approximate the quantum value of a nonlocal game, and, if so, how quickly. So far, our progress has been dismal: in spite of decades of work on this problem, we still have not even devised a *finite* time algorithm to solve it! Recent results have hinted that this might not be due to a failing of our imagination, but rather that this problem might be intrinsically hard, even undecidable (which would imply the Connes embedding conjecture is false). Thomas Vidick showed that this problem is NP-hard, and, in follow-up work with Anand Natarajan, strengthened this lower bound to QMA-hard. In this talk, I will discuss joint work with Anand, incomparable to the QMA-hardness result, which strictly improves on Thomas' original NP-hardness result. In the language of computational complexity theory, we show that NEEXP is contained in MIP*. Our result crucially uses self-testing. in particular the quantum low-degree test introduced by Anand in his previous talk.

uk: вхід без авторизації

name: Nonlocal games are harder to approximate than we thought!


An Algebraic Framework for XOR Games

uk: Математика, природничі науки

description: One promising technique for understanding features of nonlocal games is to study constraints placed on the players' measurement operators using techniques from algebraic combinatorics. In this talk, I will show an XOR game has commuting operator value 1 iff an instance of the subgroup membership problem on a finitely presented group corresponding to the game has a solution. This relationship can be used to show that the value one question is decidable for interesting sub-cases of XOR games. It also gives an algebraic framing of some open questions concerning XOR games. Based on joint work with Aram Harrow, Anand Natarajan, and Gurtej Kanwar.

uk: вхід без авторизації


uk: Математика, природничі науки

description: I will give a treatment of tensor norms of C*-algebras and operator systems with the goal of explaining the major ideas behind Kirchberg's famous tensor product reformulation of Connes' Embedding Problem.

uk: вхід без авторизації

name: Kirchberg's contributions to Connes' Embedding Problem


Matrix models for quantum permutations

uk: Математика, природничі науки

description: A quantum permutation (or magic unitary) is given by a square matrix whose entries are self-adjoint projections acting on a common Hilbert space H with the property that the row and column sums each add up to the identity operator. Quantum permutations are operator-valued analogues of ordinary permutation matrices and they arise naturally in both quantum group theory and also in the study of quantum strategies for certain non-local games. From the perspective of non-local games, it is often of great importance to know whether or not a quantum permutation (possibly satisfying some additional algebraic relations among its entries) admits a matrix model. I.e., can it be realized via operators on a finite-dimensional Hilbert space H? In this talk, I will explain how in the case of ``generic'' quantum permutations, matrix models abound. More precisely, the universal unital ∗-algebra A(N) generated by the coefficients of an N×N quantum permutation is always residually finite dimensional (RFD). Our arguments are based on quantum group and subfactor techniques. As an application, we deduce that the II1-factors associated to quantum permutation groups satisfy the Connes Embedding Conjecture. This is joint work with Alex Chirvasitu and Amaury Freslon.

uk: вхід без авторизації


uk: Математика, природничі науки

description: We provide a complete geometric description of the set of synchronous quantum correlations for the three experiment two outcome scenario. We show that these correlations form a closed set. Moreover, every correlation in this set can be realized using projection valued measures on a Hilbert space of dimension no more than 16. Along the way we discuss potential implications for Connes' embedding conjecture.

uk: вхід без авторизації

name: Geometry of the set of synchronous quantum correlations


Multiplayer XOR games and tensor norms

uk: Математика, природничі науки

description: In this expository talk I will explain the model of multiplayer XOR games with entanglement and some connections with communication complexity and quantum query algorithms. Pertaining to these connections, I will explain the relevance of various forms of the famous Grothendieck inequality, tensor norms, and variants of the Gowers uniformity norms from additive combinatorics.

uk: вхід без авторизації


Embezzlement and non-local games

uk: Математика, природничі науки

description: We explain embezzlement and survey some non-local games based on the idea of embezzlement. These games have the property that they have optimal strategies only in the limit of infinite entanglement.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Factorizable quantum channels, introduced by C. Anantharaman-Delaroche within the framework of operator algebras, have proven to have important applications in the analysis of quantum information theory, leading also to reformulations of the Connes Embedding Problem. I will survey these results, and address the question whether (infinite dimensional) von Neumann algebras are really needed to describe such channels.

uk: вхід без авторизації

name: Operator algebras meet Quantum information theory: a survey on factorizable channels and their applications


uk: Математика, природничі науки

description: We show that the convex set of factorizable quantum channels which factor through finite dimensional C*-algebras is non-closed in each dimension greater than 11, and that there exist factorizable quantum channels that require an ancilla of type II_1. The proof uses analysis of correlation matrices arising from projections, respectively, unitaries, in tracial von Neumann algebras. In recent work, we relate factorizable quantum channels to traces on a certain free product C*-algebra, via their Choi matrices. This new viewpoint leads to central questions in C*-algebra theory and to yet another formulation of the Connes Embedding Problem.

uk: вхід без авторизації

name: A new viewpoint on factorizable maps and connections to the Connes Embedding Problem


Topological free entropy

uk: Математика, природничі науки

description: Free entropy is the analogue of entropy in the setting of free probability. I will take a look back at the topoloical version of free entropy based on norm-microstates. This will include a discussion of the associated topological free entropy dimension, some connections with potential theory, random matrices and some problems.

uk: вхід без авторизації

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: The univariate moment problem for the real polynomial ring is an old problem with origins tracing back to work of Stieltjes. The multivariate moment problem has been considered more recently. Even more recently, there has been considerable interest, for both pure theory and applications, in the infinite-variate moment problem, dealing with the moment problem in (possibly not finitely generated) real commutative unital algebras. In this talk we focus on a real (commutative unital) locally multiplicatively convex topological algebra and the representation of continuous linear functionals by Radon measures on its character space. We first prove a general representation theorem by measures supported on the Gelfand Spectrum of a real sub-multiplicative semi-normed real algebra. To this end, we exploit the Archimedean Positivstellensatz, which holds in its (Banach) completion, and then proceed to handle an arbitrary locally multiplicatively convex topology. We will illustrate the methods by examples. In particular, we apply our results to the symmetric tensor algebra of a locally convex real topological space. This talk is based on joint work with Ghasemi, Infusino and Marshall.

uk: вхід без авторизації

name: The moment problem for the algebra of symmetric tensors


uk: Математика, природничі науки

description: We consider sparse Bayesian estimation in the classical multivariate linear regression model with p regressors and q response variables. In univariate Bayesian linear regression with a single response y, shrinkage priors which can be expressed as scale-mixtures of normal densities are a popular approach for obtaining sparse estimates of the coefficients. In this paper, we extend the use of these priors to the multivariate case to estimate a p times q coefficients matrix B. Our method can be used for any sample size n and any dimension p. Moreover, we show that the posterior distribution can consistently estimate B even when p grows at nearly exponential rate with the sample size n. Concentration inequalities are proved and our results are illustrated through simulation and data analysis.

uk: вхід без авторизації

name: Global-Local Shrinkage Priors for High Dimensional Multivariate Regression


Implicit Bias in Big Data Analytics

uk: Математика, природничі науки

description: Nowadays a large amount of data is available, and the need for novel statistical strategies to analyze such data sets is pressing. This talk focuses on the development of statistical and computational strategies for a sparse regression model in the presence of mixed signals. The existing estimation methods have often ignored contributions from weak signals. However, in reality, many predictors altogether provide useful information for prediction, although the amount of such useful information in a single predictor might be modest. The search for such signals, sometimes called networks or pathways, is for instance an important topic for those working on personalized medicine. We discuss a new “post selection shrinkage estimation strategy” that takes into account the joint impact of both strong and weak signals to improve the prediction accuracy, and opens pathways for further research in such scenarios.

uk: вхід без авторизації


uk: Математика, природничі науки

description: From 7:08 min there is audio interference. How knotted proteins fold has remained controversial since the identification of deeply knotted proteins nearly two decades ago. Both computational and experimental approaches have been used to investigate protein knot formation. In this talk, we introduce a new theory of knot folding that could describe a pathway for the formation of all currently known protein knot types and predict knot types that might be identified in the future. We analyze fingerprint data from crystal structures of protein knots as evidence that particular protein knots may fold according to specific configurations from our theory. In particular, our approach confirms Taylor's twisted hairpin theory of knot folding for the 31-knotted proteins and the 41-knotted KARI's as special cases, and presents an alternative folding mechanism for the 41-knotted phytochromes and the 52- and 61-knotted proteins.

uk: вхід без авторизації

name: Possible pathways for protein knot folding


keywords:
CaltechDATA
API
FAIR
FAIR software
FAIR datasets
InvenioRDM

cs: Informatika

de: Informatik

fi: tietojenkäsittelytiede

uk: Комп'ютерні науки

en: Computer Science

fr: Informatique

da: Datalogi

es: Ciencias de la Computación

nl: Informatica

uk: Бібліотекознавство, документознавство

en: Information and Library Sciences

de: Geisteswissenschaften

uk: Гуманітарні науки

en: Humanities

cs: Technické vědy

de: Ingenieurwissenschaften

fi: tekniikka

uk: Інженерія

en: Engineering Sciences

fr: Ingénierie

da: Ingeniørvidenskab

es: Ingeniería

nl: Engineering

description: A key challenge for FAIR software and datasets is creating metadata and keeping it updated. Open APIs provide an efficient way of automating metadata, and I’ll share some specific examples for both research software and datasets. We’ll look at automation I’ve created for CaltechDATA, the institutional data and software repository for Caltech. I’ll discuss current and future plans for automation in InvenioRDM, the open-source repository platform based on Zenodo and designed for institutions.

uk: вхід без авторизації

name: Helmholtz Information and Data Science Academy

name: Automating FAIR metadata for software and datasets using open APIs


Benchmarking im Wissenschaftskontext

keywords:
Benchmarking
Wissenschaftsmanagement
Hochschulmanagement
Strategisches Management

de: Wirtschaftswissenschaften

uk: Бізнес та економіка

en: Business and Economics

de: Rechts-, Wirtschafts- und Sozialwissenschaften

uk: Право, економіка та суспільні науки

en: Law, Economics and Social Sciences

description: In diesem Video erklärt Professor Ziegele die Grundlagen des Benchmarking. Anhand eines konkreten Beispiels erläutert er, wie Benchmarking im Wissenschaftskontext eingesetzt werden kann, welche Grundlagen dabei zu beachten sind und welche Vorteile die Beteiligten daraus ziehen können.

@language: de

uk: вхід без авторизації

Hochschule Osnabrück

addressCountry: DE

addressLocality: Osnabrück

addressRegion: Lower Saxony


SWOT-Analysis as a moderation technique

keywords:
SWOT-Analysis
SWOT
moderation technique
strategic management
Wissenschaftsmanagement
Hochschulmanagement
science management
university management

uk: Право, економіка та суспільні науки

description: In this Video Professor Ziegele explains, how the SWOT-Analysis can be used as a moderation technique in context of University Management. He shows how this technique can generate alot of Information about how university Managers (Vice-Presidents, Senate, University Council, Deans) see the current situation of their institution.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Diane Fritz & Steven Johnson. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Community Mapping with OpenStreetMap: a Workshop on Civic Projects


10 Years of OSM in the Classroom

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Richard Hinton. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


2020 State of the States

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Jennings Anderson. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Steven Johnson. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: A Concise Introduction to the OpenStreetMap Project


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Valerie Anderson. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Florida: State of the (Conservation) Map


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Matthew Gibb, Dr. Freddie Wills, & Dana Stuckey. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Fostering a Mapping Community in St. Louis


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Bill Wetherholt. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Integrating OSM into an undergraduate cartography curriculum


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Dominik Käuferle. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Light base map by Switzerland’s federal office of topography SwissTopo


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Daniela Waltersdorfer. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: How Could OSM Data Help City Agencies Manage Their Curb?


Maine: State of the State

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Alex Hennings. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Innisfree McKinnon. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Mapping Campus Bike Infrastructure with Students


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Benjamin Bachman. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Mapping Community Connections: Hudson Valley Mappers' Work in Poughkeepsie


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Jeff Meyer. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Mapping USA's History on OpenHistoricalMap


Microcosms in OSM

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Brian DeRocher. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Greg Hill & Celeste Reynolds. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Modeling How To Use OSM in the Classroom


The Daylight Map Distribution

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Jacob Wasserman. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


The Latest and Greatest from Mapillary

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Christopher Beddow. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Dara Carney-Nedelman & Sophia Rapp. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: The YouthMappers Network: Broad and Narrow Perspective


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Emmor Nile. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Using high resolution topography to update OSM


Using RapiD to Map Open Data

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Jeff Underwood, Yunzhi Lin, Ben Clark, & Deane Kensok. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


Welcoming New Mappers

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Clifford Snow. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


What is new on OSMCha?

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Wille Marcel. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


YouthMappers Validation Hub

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Katherine O'Byrne & Noelle Dwyer. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Monica Brandeis. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації

name: Road Quality Trends in the USA, 2018-2021


Teen Maptivists

uk: Комп'ютерні науки

description: A Mapping USA (Spring 2021) presentation by Celeste Reynolds & Greg Hill. More information about Mapping USA: https://wiki.openstreetmap.org/wiki/United_States/Events/Mapping_USA Learn more and support OpenStreetMap US at https://www.openstreetmap.us/.

uk: вхід без авторизації


keywords:
Open Data
Data Science
Remote sensing
Land Cover

uk: Комп'ютерні науки

description: Gilberto Câmara is a researcher on Geoinformatics, GIScience, Spatial Data Science, Land Use Change. and Earth Observation, working in the Image Processing Division of INPE, Brazil's National Institute for Space Research. At the OEMC project kick-off, he discussed the challenges of mapping Land Use and Land Cover in Brazil, exploring the barriers of producing global data products that are helpful for local decision-making.

uk: вхід без авторизації

name: Mapping Land Use and Land Cover: The Challenges of Going Glocal


keywords:
Open Data
Earth Observations

uk: Комп'ютерні науки

description: Stathes Hadjiefthymiades is a professor in the Department of Informatics and Telecommunications, University of Athens. Stathes presented the novel Horizon-Europe project ‘EO4EU’ which aims at making Earth Observation (EO) data more accessible by providing an AI-augmented ecosystem with improved user interfaces for EO service and data powered by extended reality. EO4EU and OEMC are sister projects and will collaborate on multiple grounds in the coming years.

uk: вхід без авторизації

name: EO4EU: AI-augmented ecosystem for EO data accessibility with XR User Interfaces for Service and Data Exploitation


uk: вхід без авторизації

name: Raman Spectroscopy and spectroscopic technique

name: Leibniz Universität Hannover (LUH), Institut für Mehrphasenprozesse (IMP)

addressLocality: Hanover

name: Projekt 'Open Education Resources with Ukraine'


uk: вхід без авторизації

name: Introduction to cell culture of human Mesenchymal Stromal Cells (hMSC)


uk: вхід без авторизації

name: Electrospinning. From Theory to Practice


uk: вхід без авторизації

name: Electrospraying Technique: Theory and Methods. Part 1


Differential Scanning Calorimetry

uk: вхід без авторизації


uk: вхід без авторизації

name: Scanning electron cryomicroscopy (CryoSEM)


Liquid Nitrogen: Safety and Uses

uk: вхід без авторизації


Materials Testing - Tensile Test

uk: вхід без авторизації

name: Leibniz Universität Hannover (LUH), Institut für Werkstoffkunde (IW)


de: Sozialwissenschaften/Soziologie

uk: Суспільні науки та соціологія

en: Social Sciences/Sociology

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Право, економіка та суспільні науки

uk: Гуманітарні науки

uk: вхід без авторизації

name: Forschungsdaten in den Geisteswissenschaften - Bereits selbstverständlich oder doch noch etwas exotisch?

name: Verein Deutscher Bibliothekarinnen und Bibliothekare e. V. (VDB)

name: Berufsverband Information Bibliothek e. V. (BIB)


Materials Testing - Hardness Testing

uk: вхід без авторизації


uk: вхід без авторизації

name: Materials Testing - Technology of Testing

name: Ukrainian State University of Science and Technology (USUST), Department of metal forming


Time-series analysis of disease data

keywords:
Open science
Health data
Computer science
Epidemiology
Time series analysis
R

uk: Комп'ютерні науки

description: In this session, Timothee Dub (Finnish Institute for Health and Welfare, Finland) & Tom Hengl (OpenGeoHub, Netherlands) discussed the basics of Time Series Analysis, including with panel data. We looked into how to take into account seasonality, how to identify a trend and how to investigate the relationship between two-time series, with a focus on practical tips and R packages. By the end of this lecture, participants are able to analyze surveillance data, identify seasonality and investigate potential trends.

uk: вхід без авторизації


Covariate data and spatial mapping

keywords:
Open science
Data modeling
Disease data
Covariates
Spatial models

uk: Комп'ютерні науки

description: This talk first touched on why we use maps at all then look at the factors (“covariates”) that drive disease occurrence. The session led by William Wint (E.R.G.O., UK) & Cederic Marsboom (Avia-GIS, Belgium) examines what these covariates might be and identify the environmental, agricultural, socio-economic, ecological and climatic parameters that can best contribute to spatial modelling. It is also important to know where these data can be found, what are the pros and cons of different data sources for the common covariate variables, and what datasets can be used for different types of models. The available covariate data are not always in a form that is convenient for spatial modellers and the session will provide examples of the processing and selection needed to provide modellers with what they need. Finally, the use of selected covariates in spatial models is be discussed and illustrated with worked examples.

uk: вхід без авторизації


uk: Математика, природничі науки

description: The Feynman propagator is at the heart of quantum field theory. However, in quantum field theory in curved spacetimes, no locally covariant notion of a distinguished Feynman propagator exists. Instead, often a distinguished class of Feynman propagators is considered, which share a common parametrix. Nevertheless, certain classes of spacetimes possess distinguished Feynman propagators. First, I will give an in-depth introduction to propagators (Green functions) on curved spacetimes and their role in quantum field theory. In particular, I will highlight the importance of the so-called Hadamard states – an appropriate generalization of the Poincaré invariant vacuum state. Then, I will show that the free Klein–Gordon field on asymptotically static spacetimes comes equipped with a natural Feynman propagator (albeit globally constructed and generally not related to a state). Finally, I will argue that this Feynman propagator is closely related to the question of the self-adjointness of the Klein–Gordon operator on L2(spacetime) and the boundary value of its resolvent.

uk: вхід без авторизації

name: Feynman Propagators and the Self-Adjointness of the Klein–Gordon Operator

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


Holographic Tensors

uk: Математика, природничі науки

description: The theory of random tensors is expanding rapidly in scope. At the combinatorial (zero dimensional) level the tensorial 1/N expansion has a much more complicated structure than 'tHooft 1/N expansion for matrices, but it is led by a simpler class of graphs, called melonic. Adding time to the picture gives quantum mechanical tensor models which generalize in a promising way the Sachdev-Ye-Kitaev model of near AdS2/CFT1 holographic correspondence. We shall review this fast growing topic.

uk: вхід без авторизації


Mean-field Quantum Electrodynamics

uk: Математика, природничі науки

description: I will review several results obtained in collaboration with Philippe Gravejat, Christian Hainzl and Eric Séré on a mean-field model in QED. I will particularly discuss charge renormalization and the derivation of the Euler-Heisenberg effective Lagrangian. I will also mention the advantages and disadvantages of the model, as well as open problems.

uk: вхід без авторизації


uk: Математика, природничі науки

description: I shall discuss a class of nonequilibrium states in CFT in one space dimension and how heat transport in such states connects to the representation theory of the group of circle diffeomorphisms.

uk: вхід без авторизації

name: Heat waves in 1+1-dimensional Conformal Field Theory


uk: Математика, природничі науки

description: An outstanding problem in the area of rigorous renormalization group theory is to develop a Wilsonian formalism which can handle space-dependent couplings in the Euclidean setting. I will present such a method in the simpler hierarchical model case and explain how this allowed us to prove a 46 years old prediction by Wilson regarding the anomalous scaling of the square/energy field in a hierarchical ferromagnet. The model we studied is a hierarchical version of a 3d ferromagnet with long-range interactions in a range of parameters which puts it slightly below the upper critical dimension. We constructed the scaling limit for the joint law of the elementary/spin field together with the square/energy field as well as all mixed correlation functions. The Euclidean version of this scaling limit is conjectured to be a conformal field theory in three dimensions according to recent work by physicists in the conformal bootstrap program. There is a natural analogue of conformal invariance in the hierarchical model which thus provides an ideal testing ground for renormalization group-based attempts at rigorously proving conformal invariance. The idea is to feed the space-dependent renormalization group space-dependent ultraviolet cutoffs. I will also mention emerging connections to the AdS/CFT correspondence.

uk: вхід без авторизації

name: Space-dependent RG, anomalous dimensions in a hierarchical model for 3d CFT and connections to the AdS/CFT correspondence


uk: Математика, природничі науки

description: I will discuss some recent progress on infrared problems in non-perturbative approaches to QED. First, I will explain the general distinction between the `infraparticle’ and `infravacuum’ picture of the electron which pertains to the existence resp. non-existence of the spacelike asymptotic flux of the electric field. On this basis the problem of electron-photon scattering will be discussed both in models of non-relativistic QED and in the setting of algebraic QED. On the infraparticle side, we will revisit the Faddeev-Kulish approach, theory of particle weights and the problem of velocity superselection. On the infravacuum side the talk will cover Kraus-Polley- Reents representations and the Buchholz-Roberts approach. If time allows, relations to a current trend in high-energy physics triggered by the works of A. Strominger et al. on the Weinberg's soft-photon theorems will be discussed. (Joint work with A. Pizzo)

uk: вхід без авторизації

name: The infrared problems in QED: Some topics of current research


Renormalization of Yang-Mills theories

uk: Математика, природничі науки

description: The non-abelian Yang-Mills self-interaction is marginal in four dimensions in the usual terminology of the renormalization group, and thus requires renormalization to all orders in an expansion (in either the coupling or a loop expansion). It is well-known in principle how to reconcile UV-renormalization with local gauge invariance, but a fully rigorous and satisfactory treatment taking also into account the problems posed by the complicated IR-behavior of the theory on non-compact manifolds has only been given relatively recently. In this talk, I describe how a combination of the Epstein-Glaser method/method of renormalization group flow equations and cohomological techniques a la Batalin-Vilkovisky can be used to establish the existence of correlation n-point functions of arbitrary gauge invariant local operators to arbitrary orders in perturbation theory. The second method of proof comes by construction with rather refined bounds for these objects capturing their short and long distance properties. Time permitting, I furthermore explain how the operator product arises in this context.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In searches for new phenomena in particle physics, we are often interested in observing tiny deviations from the Standard Model (SM) predictions. In consequence, the SM predictions must be known very precisely. This is often a challenge even in situations when purely perturbative calculations are sufficient. At present, the most powerful methods amount to expressing the observables of interest in terms of so-called Master Integrals (MIs). The MIs are not being evaluated directly but rather via solving systems of differential equations. In the process of finding the MIs via the Laporta algorithm, large numbers (often billions) of linear equations need to be generated and solved, with simplifications of complicated rational functions at each step. In consequence, even the most powerful present-day computer clusters are sometimes insufficient. The situation could radically improve if a clever mathematical solution of the considered algebraic problem could be found in general.

uk: вхід без авторизації

name: Perturbative calculations in QFT and the Laporta algorithm


uk: Математика, природничі науки

description: I will give an overview of how the Batalin-Vilkovisky (BV) formalism can be incorporated into perturbative algebraic quantum field theory in full generality and I will discuss two examples: gauge theories and effective quantum gravity. In the latter case, there is an additional difficulty in constructing gauge-invariant observables. I will explain how this is addressed in our approach.

uk: вхід без авторизації

name: BV quantization in perturbative AQFT: gauge theories and effective quantum gravity


uk: Математика, природничі науки

description: In QFT on curved spacetimes, a central difficulty is how to reconcile local properties of states (short-distance behaviour of N-point functions) with global ones (positivity, spacetime or gauge symmetries, asymptotic convergence to vacuum or thermal state, boundary conditions, etc.). In the last few years, these difficulties have been overcome in a wide range of situations, leading in particular to rigorous descriptions of thermal effects on black hole spacetimes. The aim of the talk will be to present the new state-of-the-art and discuss the main conjectures, with a particular focus on: - distinguished states on black hole spacetimes and their thermal properties - Hadamard states and (generalized) Feynman propagators in scattering situations - the Reeh-Schlieder property - states with good holographic properties on AdS spacetimes (Joint work with Ch. Gerard)

uk: вхід без авторизації

name: Propagators and distinguished states on curved spacetimes


uk: Математика, природничі науки

description: We analyze some properties shown by extremal KMS states for interacting massive scalar fields propagating over Minkowski spacetime. These states have been recently constructed in the framework of perturbative algebraic quantum field theories by Fredenhagen and Lindner. In particular, we discuss the validity of the return to equilibrium property when the interaction Lagrangian has compact spatial support. If the adiabatic limit is considered, the return to equilibrium is in general not valid. This implies that an equilibrium state under the adiabatic limit for a perturbative interacting theory evolved with the free dynamics does not converge to the free equilibrium state. Actually, we show that the ergodic mean of this state converges to a non-equilibrium steady state (NESS) for the free theory. We thus compute the relative entropy among equilibrium states for different evolutions showing that such an extent is compatible with perturbation theory. We then analyze the entropy production in the NESS discussed above to estimate how far from equilibrium is this state.

uk: вхід без авторизації

name: Thermal states in perturbative algebraic quantum field theory: stability, relative entropy and entropy production


uk: Математика, природничі науки

description: Starting with proposals by Schuster and Toro (2013), the massless "continuous-spin" or "infinite-helicity" irreducible representations of the Poincaré group have been the subject of several recent investigations. Their status as string-localizable particles was shown in principle by Mund, Schroer and Yngvason (2006). From the viewpoint of Wigner's equations of motion for such (as yet unobserved) particles, we endeavour to give a first-quantized approach to them, based on a background of classical elementary systems.

uk: вхід без авторизації

name: Wigner's "continuous-spin" representations reconsidered


uk: Математика, природничі науки

description: The conformal bootstrap seeks to use conformal symmetry, associativity of the operator product expansion, and other physical consistency conditions to constrain nontrivial conformal field theories (CFTs). I will review recent progress in the conformal bootstrap, including Rattazzi, Rychkov, Tonni, and Vichi's algorithm for deriving bounds on CFT data, bounds on the 3d critical Ising model, and some analytic results about the bootstrap equations.

uk: вхід без авторизації

name: The conformal bootstrap in d>2 dimensions


uk: Математика, природничі науки

description: We establish the Haag-Kastler axioms for a class of interacting quantum field theories on the twodimensional de Sitter space, which satisfy finite speed of light. The P(φ)2 model constructed by Barata, Jäkel & Mund, describing massive scalar bosons with polynomial interactions, provides an example.

uk: вхід без авторизації

name: The Haag-Kastler Axioms on Two-dimensional De Sitter Space


AQFT and VOAs

uk: Математика, природничі науки

description: We have two different axiomatic approaches to chiral conformal field theory (CFT). The conformal net approach is based on the theory of operator algebras on Hilbert spaces (C^*-algebras and von Neumann algebras) and it is the chiral CFT version of algebraic quantum field theory (AQFT). On the other hand, the vertex operator algebra (VOA) approach is based on an algebraic reformulation of the relevant properties of conformal invariant quantum fields on the circle.

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: A DISCRETE STOCHASTIC INTERPRETATION OF THE DOMINATIVE p -LAPLACIAN


Heat Flow on Metric Random Walk Spaces

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

description: Diffuse interface models based on the phase field methodology have been developed for various free boundary problems. They involve representing the interfaces by thin layers. Some applications feature phenomena on the interfaces described by PDEs for interface resident fields. We will address the questions of how to model such phenomena in the diffuse interface setting and how to numerically approximate the solutions, which may require special consideration due to degeneracies. The approach can be generalised to networks and bubble clusters. One key challenge then is to correctly recover the conditions in the triple junctions formed by three interfaces. The research is motivated by surface active agents (surfactants) in multi-phase flow which can be effectively modelled by Cahn-Hilliard-Navier-Stokes systems. Some preliminary results for a novel numerical scheme will be presented, as well as some simulations to support the theoretical findings.

uk: вхід без авторизації

name: On a diffuse interface approach to PDEs on surfaces and networks


uk: Математика, природничі науки

description: We present two simple and efficient algorithmic frameworks using signed distance functions. The first one is a numerical scheme for computing certain area reserving geometric motion of curves in the plane, such as area preserving motion by curvature. The second is a general technique for integrating over curves and surfaces that are not defined by any explicit parameterization. This method is based on rewriting the curve or surface integral as a volumetric integral formulation over the ambient space. We show applications of both methods.

uk: вхід без авторизації

name: Applications of distance functions to motions of curves in the plane, and integration over interfaces and unstructured point sets


uk: Математика, природничі науки

description: A dynamic boundary value problem of the level-set mean curvature flow equation is discussed. We first give a unique existence result of viscosity solutions for more general singular degenerate parabolic equations. The comparison principle is established by employing a so-called flattening argument to avoid a singularity of the equation, while we prove existence of solutions by Perron's method. We also provide a deterministic discrete game interpretation for this problem. The original version of this game was introduced by Kohn and Serfaty (2006) for the case with no boundary, and we propose a modified game including a kind of reflection near the boundary so that the corresponding value functions converge to a viscosity sub-/supersolution satisfying a dynamic boundary condition. This talk is based on a joint work with Y. Giga (The University of Tokyo) and Q. Liu (Fukuoka University).

uk: вхід без авторизації

name: On a dynamic boundary value problem of the level-set mean curvature flow equation


uk: Математика, природничі науки

description: I will discuss on the evolution of sets in mean curvature flows with forcing, where the forcing term encourages the sets to have finite, non-zero volume. We will focus on preservation of a strong version of star-shaped geometry throughout the evolution, which enables us to discuss stability and long-time behavior of the flow.

uk: вхід без авторизації

name: Volume preserving Mean-curvature flow with star-shaped sets


uk: Математика, природничі науки

description: We demonstrate that a class of one and two phase free boundary problems can be recast as nonlocal parabolic equations on a codimension one submanifold. The canonical examples would be one-phase Hele-Shaw and Laplacian growth. In the special class of free boundaries that are graphs over Rd, we give a precise characterization that shows their motion is equivalent to that of a solution of a nonlocal (fractional) and nonlinear parabolic equation in Euclidean space. Our main observation is that the free boundary condition defines a nonlocal operator having what we call the Global Comparison Property. A consequence of the connection with nonlocal parabolic equations is that for free boundary problems arising from translation invariant elliptic operators in the positive and negative phases, one obtains, in a uniform treatment for all of the problems, a propagation of modulus of continuity for weak solutions of the free boundary flow. This is based on joint works with Hector Chang-Lara and Russell Schwab.

uk: вхід без авторизації

name: Free boundary problems as parabolic Integro-differential equations


uk: Математика, природничі науки

description: We propose a fully discrete numerical scheme for solving an advection– diffusion equation on a family of evolving hypersurfaces. The method is based on a diffuse interface approach that combines a level set description of the moving surfaces with a discretization by linear finite elements in space and a backward Euler scheme in time. We estimate the error in L∞(L2) and L2(H1) in terms of the spatial grid size h, the time step τ and the thickness of the diffuse interface. Furthermore, we present the results of test calculations that support our analysis.

uk: вхід без авторизації

name: Stability and error analysis for a diffuse interface approach to an advection–diffusion equation on a moving surface

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: We present variational formulations of mean curvature flow and surface diffusion for axisymmetric hypersurfaces in R^3. On recalling important properties of the schemes introduced by the authors for the corresponding geometric evolution equations for closed curves in the plane, we introduce suitable finite element approximations, and investigate their stability and vertex distribution properties. (joint work with John W. Barrett and Harald Garcke)

uk: вхід без авторизації

name: Numerical approximation of axisymmetric geometric evolution equations


uk: Математика, природничі науки

description: We review our recent strategy to prove existence, uniqueness as well as the convergence of a time discrete scheme to the curvature flow of a perimeter defined by a non-smooth (crystalline) surface tension.

uk: вхід без авторизації

name: Recent results on crystalline curvature flows


uk: Математика, природничі науки

description: In the talk, we consider a gradient flow of the total variation in the negative Sobolev space H−s, s∈[0,1], under the periodic boundary condition. We derive a dual formulation of a convex variational problem associated with a semi-implicit time discretization of this flow. Based on the forward-backward scheme, we construct a minimizing sequence of a given functional and discuss issues concerning its convergence. We also show and compare results of numerical experiments for simple initial data and different values of the index s. This is joint work with Y. Giga (University of Tokyo) and P. Rybka (University of Warsaw).

uk: вхід без авторизації

name: The forward-backward scheme for the minimizing total variation flow in H−s


uk: Математика, природничі науки

description: A well-known folklore in combustion community is that curvature effect in general slows down flame propagation speeds because it smooths out wrinkled flames. As the first theoretical result in this direction, we prove that the effective flame speed is decreasing with respect to curvature diffusivity (Markstein number) for shear flows in the level-set G-equation model. The proof involves several novel and rather sophisticated inequalities arising from the nonlinear structure of the equation. We also show similar phenomenon in non-shear flows numerically. This is joint work with Jiancheng Lyu and Yifeng Yu.

uk: вхід без авторизації

name: Curvature effect in shear flow: slowdown of flame speeds with Markstein number


uk: Математика, природничі науки

description: Advances in materials science have enabled the observation and control of microstructures such as nanoscale defects with remarkable precision. In this talk, I will discuss recent progress and open challenges in understanding how small-scale details in the kinetics of crystal surfaces can macroscopically influence the surface morphological evolution. In particular, the evolution of crystal surface plateaus, facets, is characterized by an effective behavior at the macroscale that is not necessarily only the outcome of averaging, but instead may be dominated by certain discrete (microscopic) events. This "idiosyncrasy" of facet evolution raises challenging but interesting mathematical questions. My talk will explore via selected examples and methods how the kinetics of microscale defects near facets can plausibly leave their imprints to continuum-scale problems, at larger scales. The main tool is a fourth-order nonlinear PDE for the surface height profile. I will address and provide an answer to the question: Can this continuum description be reconciled with the motion of line defects (steps) at the nanoscale, and how?

uk: вхід без авторизації

name: On the mathematical modeling of crystal facets: A PDE approach with a touch of discreteness


uk: Математика, природничі науки

description: Epitaxial growth is an important physical process for forming solid films or other nano-structures. It occurs as atoms, deposited from above, adsorb and diffuse on a crystal surface. Modeling the rates that atoms hop and break bonds leads in the continuum limit to degenerate 4th-order PDE that involve exponential nonlinearity and the p-Laplacian with p=1, for example. We discuss a number of analytical results for such models, some of which involve subgradient dynamics for Radon measure solutions.

uk: вхід без авторизації

name: Dynamics of a degenerate PDE model of epitaxial crystal growth


uk: Математика, природничі науки

description: The Peierls-Nabarro model was first introduced by Peierls Nabarro to describe the continuum model of dislocation in materials. It incorporates the atomic effect into the continuum framework and give us an understanding of dislocation core structure. Our main goal is to determine the displacement in the whole space using Perierls-Nabarro (PN) model, which incorporates the atomic effect into the continuum framework. We focus on the existence of analytic solution to Peierls-Nabarro model including stationary model and dynamic model. Since we incorporate the misfit surface energy into total energy of the system, which leads to a nonlinear boundary condition, the strategy is to first decouple the displacement field and then to uniquely solve a nonlocal equation on boundary.

uk: вхід без авторизації

name: Steady and Dynamic Solutions to nonlocal Peirtls-Nabarro for Dislocation


uk: Математика, природничі науки

uk: вхід без авторизації

name: Numerical Scheme of S0(3)-valued TV flows


Anisotropic TV flow in 2D case

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: On some 1 -dimensional flux limited diffusion equations


uk: Математика, природничі науки

description: In this talk we consider evolving spirals by crystalline eikonal-curvature flow in the plane. Our focus on this issue is to propose a framework to treat the evolution of several spirals with singular diffusion by L^1 type regularization, and merging with each other. For this purpose, we consider this motion with the minimizing movement approach based on the algorithm proposed by Chambolle in 2004. This approach considers the motion of interfaces as the minimizing movement of the singular surface energy and distance from the original interface. Note that the distance is measured by the signed distance function of the interface. However, the signed distance is not well-defined since a spiral curve does not divide the domain into inside and outside of the curve. To overcome this issue, we introduce two approaches; construct a signed distance function only around the curve, or using general level set function for spirals instead of the signed distance. We present several numerical results, which is established with the split Bregman iteration. This is a joint work with Y.-H. R. Tsai.

uk: вхід без авторизації

name: Minimizing movement approach using general level set functions for evolving spirals by crystalline curvature flow


uk: Математика, природничі науки

description: In this talk I will present recent results concerning the level set formulation of the crystalline mean curvature flow. In a joint work with Yoshikazu Giga, we introduce a new notion of viscosity solutions for this problem and establish its well-posedness for compact crystals in an arbitrary dimension as well as the stability with respect to an approximation by a smooth anisotropic mean curvature flow. Since the crystalline mean curvature might not be defined even for smooth surfaces, we consider a restricted class of "faceted" test functions and show that it is sufficiently large to yield a general comparison principle.

uk: вхід без авторизації

name: Viscosity solutions for the crystalline mean curvature flow


uk: Математика, природничі науки

description: There has been some recent interest in exploring applications of fractal calculus in transport models. One of the motivations for this is that such models are able to generate anomalous transport signals. For example, when fractional calculus is employed to define diffusion transport fluxes (heat, mass etc.) the exponent n in the space-time scaling differs from the classical value of n = Â˝. In this talk we have two objectives. The first objective is to identify physically realizable systems that exhibit anomalous transport behaviors. The second is to arrive at suitable fractional governing equations that can model these systems. To these ends we will build direct simulations of the infiltration of moisture into a porous media containing a distribution of flow obstacles. When the obstacles form a repeating pattern, this problem can be viewed as a limit case of the classical one-phase Stefan melting problem and the measure of the advance of the infiltration length changes with the square root of time. When the obstacles are distributed in a fractal pattern, however, the infiltration shows a sub-diffusive behavior, where the time exponent is less that the square root. Through considering the time scaling of Brownian motion in a fractal obstacle filed we are bale to directly associate this sub-diffusive time exponent to the fractal dimension of the obstacle filed. This in turn, allows us to develop fractional calculus based governing equations, with a closed particular solution, for moisture infiltration into a fractal obstacle field. The talk will close with considerations as to how these findings can be associated with more general Stefan problem that incorporated fractional calculus treatments.

uk: вхід без авторизації

name: Anomalous Infiltration into Heterogeneous Porous Media: Simulations and Fractional Calculus Models


uk: Математика, природничі науки

description: We will introduce an extended notion of viscosity solutions for initial-boundary value problems of second order fully nonlinear PDEs that include Caputo time fractional derivatives of order less than one. As is the integer-order case, the unique existence is established by the comparison principle and Perron's method. Stability with respect to the order of time derivative is provided by the half-relaxed limit method.

uk: вхід без авторизації

name: Well-posedness of fully nonlinear PDEs with Caputo time fractional derivatives


Existence of 1-harmonic map flow

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Nonlinear and Nonlocal Degenerate Diffusions on Bounded Dom ains


uk: Математика, природничі науки

description: We show that the uniform boundedness of the transcendental Brauer group of K3 surfaces and abelian varieties of bounded dimension defined over number fields of bounded degree is a consequence of a conjecture of Coleman about rings of endomorphisms of abelian varieties. We also show that this conjecture of Coleman implies the conjecture of Shafarevich about the N\'eron-Severi lattices of K3 surfaces. This is a joint work with Martin Orr and Yuri Zarhin.

uk: вхід без авторизації

name: On uniformity conjectures for abelian varieties and K3 surfaces over number fields


uk: Математика, природничі науки

description: We consider a family of abelian varieties over a number field K , i.e. a variety X with a map to a curve B whose fibres are abelian varieties (the interesting cases are when B is the projective line or an elliptic curve with positive rank). The generic fibre is an abelian variety over the function field K(B) and the group of K(B)-rational points has a rank r. For almost all points t in B(K) the fibre is an abelian variety Xt over K and the group of K-rational point has rank r(t). A specialisation theorem of Silverman says that for or almost all points t in B(K) the rank r(t) is greater or equal to r. We want to understand the distribution of r(t), in particular we ask wether there are infinitely many t's 1) with r(t)=r, 2) with r(t)>r. The problem looks very hard in general, but, under specific geometric conditions, we will settle the second question, and provide interesting example where much more can be proven. This is a joint work with Cecília Salgado.

uk: вхід без авторизації

name: Variation of the Mordell-Weil rank in families of abelian varieties


uk: Математика, природничі науки

description: What can we say about the variation of the rank in a family of elliptic curves ? We know in particular that if infinitely many curves in the family have non-zero rank, then the set of rational points is Zariski dense in the associated elliptic surface. We use a “conjectural substitute” for the geometric rank (or rather for its parity) : the root number. For a non-isotrivial family, under two analytic number theory conjectures I show that the root number is -1 (resp. +1) for infinitely many curves in the family. On isotrivial families however, the root number may be constant : I describe its behaviour in this case.

uk: вхід без авторизації

name: Variation of the root number in families of elliptic curves

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: Let d and g be positive integers with 1<d<g. If d is odd, we prove there exists B(d)>0 such that a positive proportion of odd genus g hyper elliptic curves over Q have at most B(d) points of degree d. If d is even, we similarly bound the degree d points not pulled back from degree d/2 points of the projective line. Our proof proceeds by refining Park’s recent application of tropical geometry to symmetric power Chabauty, and then applying results of Bhargava and Gross on average ranks of Jacobians of hyperelliptic curves.

uk: вхід без авторизації

name: Irrational points on random hyperelliptic curves


uk: Математика, природничі науки

description: A topic of current interest regards 'how often' a variety has a rational point. This topic was initially studied by Serre who gave upper bounds in the case of families of conics parametrised by a projective space. In the last few years this topic has been significantly enriched by Loughran and others. I will begin by giving an overview of the latest developments and finish by discussing joint work with Erik Visse, where asymptotics are given for a family of conics parametrised by arbitrary smooth hypersurfaces of low degree.

uk: вхід без авторизації

name: The behavior of rational points in families


uk: Математика, природничі науки

description: In the 1950s Lang studied the properties of C1 fields, that is, fields over which every hypersurface of degree at most n in a projective space of dimension n has a rational point. Later he conjectured that every smooth proper rationally connected variety over a C1 field has a rational point. I will explain how to find rational points on rationally connected threefolds over C1 fields of characteristic 0.

uk: вхід без авторизації

name: Rational points over C1-fields of characteristic 0


uk: Математика, природничі науки

description: A famous theorem due to Erdős and Kac states that the number of prime divisors of an integer N behaves like a normal distribution. In this talk we consider analogues of this result in the setting of arithmetic geometry, and obtain probability distributions for questions related to local solubility of algebraic varieties. This is joint work with Efthymios Sofos.

uk: вхід без авторизації

name: An Erdős-Kac law for local solubility in families of varieties


uk: Математика, природничі науки

description: Given a curve of genus at least 2, it was proven in 1983 by Faltings that it has only finitely many rational points. Unfortunately, this result is ineffective, in that it gives no bound on the number of rational points. 40 years earlier, Chabauty proved the same result under the condition that the rank of the Jacobian of the curve is strictly smaller than the genus. While this is obviously a weaker result, the methods behind that proof could be made effective, and this was done by Coleman in 1985. Coleman's work led to a procedure known as the Chabauty-Coleman method, which has shown to be extremely effective at determining the set of rational points exactly, particularly in the case of hyperelliptic curves. In this talk I will discuss how we implement this method using Magma and Sage to provably determine the set of rational points on a large set of genus 3, rank 1 hyperelliptic curves, and how these calculations fit into the context of the state of the art conjectures in the field.

uk: вхід без авторизації

name: Chabauty-Coleman experiments for genus 3 hyperelliptic curves


uk: Математика, природничі науки

description: We propose a 2-cover method to study rational points on elliptic surfaces. We apply it to several isotrivial Kummer-type families whose generic Mordell-Weil ranks are 0 so that geometric argument may fail and we show that for these families rational points are Zariski dense and even dense in real topology, which is thereby in favor of a conjecture of Mazur.

uk: вхід без авторизації

name: Density of rational points on certain elliptic K3 surfaces


uk: Математика, природничі науки

description: A classical result of Colliot-Thélène and Sansuc states that the only obstruction to the Hasse principle and weak approximation for generalised Châtelet surfaces is the Brauer-Manin one, conditionally on Schinzel's hypothesis. Inspired by their work, we study the analogous questions concerning the existence and the density of integral points on the corresponding affine surfaces, again under Schinzel's hypothesis. To be precise, we show that the Brauer-Manin obstruction is the only obstruction to the integral Hasse principle for an infinite family of generalised affine Châtelet surfaces. Moreover, we show that the set of integral points on any surface in this family satisfies a strong approximation property off infinity with Brauer-Manin obstruction.

uk: вхід без авторизації

name: Integral points on generalised affine Châtelet surfaces


uk: Математика, природничі науки

uk: вхід без авторизації

name: Verifying Zariski density of rational points on del Pezzo surfaces of degree 1


uk: Математика, природничі науки

description: Let l be a positive integer. We discuss improved average bounds for the l-torsion of the class groups for some families of number fields, including degree-d-fields for d between 2 and 5. The improvements are based on refinements of a technique due to Ellenberg, Pierce and Wood.

uk: вхід без авторизації

name: Average bounds for l-torsion in class groups


uk: Математика, природничі науки

description: Masser and Vaaler gave an asymptotic formula for the number of algebraic numbers of given degree and increasing height. This problem was solved by counting lattice points in an expanding star body. We'll explain how to estimate the volumes of slices of star bodies, which allows one to count algebraic integers, algebraic integers of given norm and/or trace, and more. There will be pictures.

uk: вхід без авторизації

name: Slicing the stars: counting algebraic numbers


uk: Математика, природничі науки

description: After fixing numerical invariants such as dimension, it is natural to ask which birational classes of varieties fail the Hasse principle, and moreover whether the Brauer group (or certain distinguished subsets) explains this failure. In this talk, we will focus on K3 surfaces (e.g. a double cover of the plane branched along a smooth sextic curve), which have been a testing ground for many conjectures on rational points. In 2014, Ieronymou and Skorobogatov asked whether any odd torsion in the Brauer group of a K3 surface could obstruct the Hasse principle. We answer this question in the affirmative for transcendental classes; via a purely geometric approach, we construct a 3-torsion transcendental Brauer class on a degree 2 K3 surface over the rationals with geometric Picard rank 1 (hence with trivial algebraic Brauer group) which obstructs the Hasse principle. Moreover, we do this without needing a central simple algebra representative. This is joint work with Tony Varilly-Alvarado.

uk: вхід без авторизації

name: Odd order transcendental obstructions to the Hasse principle on general K3 surfaces


uk: Математика, природничі науки

description: It is widely expected that, if a curve over a global field has no rational points, that there is an obstruction to existence of rational points coming from the Brauer group. One piece of evidence for this is an heuristic due to Poonen. We show that Poonen's argument also applies to p-primary subgroups of the Brauer group (for any prime p) but that there are examples of curves with no rational point but not having an obstruction coming from the p-primary subgroups of the Brauer group. Joint work with B. Creutz and B. Viray.

uk: вхід без авторизації

name: Obstructions to existence of rational points on curves from subgroups of the Brauer group


uk: Математика, природничі науки

uk: вхід без авторизації

name: Manin's conjecture for a bi-projective variety


uk: Математика, природничі науки

description: We discuss small solutions to ternary diagonal inequalities of any degree where all of the variables are assumed to be of size P. We study this problem on average over a one-parameter family of forms and discuss a generalization of work of Bourgain on generic ternary diagonal quadratic forms to higher degree. In particular we discuss how these Diophantine inequalities are related to counting rational points close to varieties.

uk: вхід без авторизації

name: Diophantine inequalities for ternary diagonal forms


uk: Математика, природничі науки

description: There has been much interest recently in bounding the Brauer groups of K3 surfaces over number fields. On the other hand, the arithmetic of integral points on log K3 surfaces appears to share some features with that of rational points on K3 surfaces. Some of the simplest examples of log K3 surfaces are the open surfaces obtained by starting with a projective del Pezzo surface and removing a smooth anticanonical divisor. We use Merel's boundedness of torsion on elliptic curves to prove boundedness of the Brauer groups of such log K3 surfaces over a number field. This is joint work with Julian Lyczak.

uk: вхід без авторизації

name: A uniform bound on the Brauer groups of certain log K3 surfaces


uk: Математика, природничі науки

description: This is joint with Jordan Ellenberg and Matt Satriano.

uk: вхід без авторизації

name: Counting points, counting fields, and heights on stacks


Quartic forms in 30 variables

uk: Математика, природничі науки

description: We will prove that smooth Quartic hypersurfaces satisfy the Hasse Principle as long as they are defined over at least 30 variables. The key tool here is employing Kloosterman's version of circle method. This is a joint work with Oscar Marmon (U Lund).

uk: вхід без авторизації

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: Yongqi Liang has shown that for rationally connected varieties over a number field K, sufficiency of the Brauer-Manin obstruction to the existence of rational points over all finite extensions of K implies sufficiency of the Brauer-Manin obstruction to the existence of zero-cycles of degree 1 over K. I will discuss joint work with Francesca Balestrieri where we extend Liang's result to Kummer varieties.

uk: вхід без авторизації

name: Arithmetic of rational points and zero-cycles on Kummer varieties


uk: Математика, природничі науки

description: For an abelian variety A over a number field K, a consequence of the Birch and Swinnerton-Dyer conjecture is the 2-parity conjecture: the global root number agrees with the parity of the 2-infinity Selmer rank. It is a standard result that the root number may be expressed as a product of local terms and we show that, over any quadratic extension of K, the same holds true for the parity of the 2-infinity Selmer rank. Using this we prove several new instances of the 2-parity conjecture for general principally polarised abelian varieties by comparing the local contributions arising. Somewhat surprisingly, the local comparison relies heavily on results from the theory of quadratic forms in characteristic 2.

uk: вхід без авторизації

name: Parity of 2-Selmer ranks of abelian varieties over quadratic extensions


uk: Математика, природничі науки

description: Already 190 years ago Jacobi in a paper in Crelle's journal described the celebrated closure theorem of Poncelet as a ``bekanntes Problem der Elementargeometrie''. Some natural number theoretical questions arising in this context, will be discussed during this talk.

uk: вхід без авторизації

name: Two arithmetical aspects of Poncelet's closure theorem


The Coming of the Golden Age

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: Protein DNA recognition by Hox-cofactors complexes


uk: Математика, природничі науки

uk: вхід без авторизації

name: Gene regulatory network rewiring by disease variants and transcription factor isoforms


uk: Математика, природничі науки

uk: вхід без авторизації

name: Distal substitutions alter conformational space to create new functions among paralogous transcription factors


uk: Математика, природничі науки

uk: вхід без авторизації

name: Direct and indirect influences that adjacent C2H2 zinc fingers have on DNA-binding strategies


uk: Математика, природничі науки

uk: вхід без авторизації

name: Novel mechanism of bispecificity in forkhead transcription factors


uk: Математика, природничі науки

uk: вхід без авторизації

name: Higher-order chromatin structure: The role of Mediator


uk: Математика, природничі науки

uk: вхід без авторизації

name: Accurate and sensitive quantification of protein-DNA binding affinity


uk: Математика, природничі науки

uk: вхід без авторизації

name: Integration of local and regional cis-regulatory information


uk: Математика, природничі науки

uk: вхід без авторизації

name: Binding site location in E.coli promoters and Conceptual issues on gene regulation


uk: Математика, природничі науки

uk: вхід без авторизації

name: Probing effects of flanking sequence via high-resolution measurements of millions of TF-DNA binding energies


uk: Математика, природничі науки

uk: вхід без авторизації

name: Transcription factors operate across disease loci: Epstein-Barr Virus EBNA2 in autoimmunity


uk: Математика, природничі науки

uk: вхід без авторизації

name: Transcription factor crosstalk during developmental differentiation


uk: Математика, природничі науки

uk: вхід без авторизації

name: SMILE-seq-based analysis of DNA binding specificities of human KRAB zinc-finger proteins


uk: Математика, природничі науки

uk: вхід без авторизації

name: A protein-protein interaction of adjacent C2H2 zinc fingers controls binding geometry and the residues able to specify DNA targets

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

uk: вхід без авторизації

name: A unified approach for quantifying and interpreting DNA shape readout by transcription factors


uk: Математика, природничі науки

uk: вхід без авторизації

name: The effects of sequence and mismatches on Cas9 activity


uk: Математика, природничі науки

uk: вхід без авторизації

name: Molecular principles for optimizing protein-DNA interactions


uk: Математика, природничі науки

uk: вхід без авторизації

name: A tale of DNA shape analysis: a user manual and next steps


DNA shape – intrinsic or induced?

uk: Математика, природничі науки

uk: вхід без авторизації


Modified cytosine and DNA binding

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: The ENCODE Encyclopedia of candidate cis-regulatory elements and transcription factor binding sites


uk: Математика, природничі науки

uk: вхід без авторизації

name: Combinatorial recognition of DNA by bZIP transcription factors


uk: Математика, природничі науки

uk: вхід без авторизації

name: Deep learning for protein-RNA interactions


uk: Математика, природничі науки

uk: вхід без авторизації

name: How adaptive immunity constrains composition and fate of large bacterial populations


uk: Математика, природничі науки

uk: вхід без авторизації

name: Cell to cell communication by diffusible molecules


uk: Математика, природничі науки

uk: вхід без авторизації

name: The Ecology of Stem Cells: On the rise and fall of a differentiating community


uk: Математика, природничі науки

uk: вхід без авторизації

name: From molecules to development: understanding design principles of biological oscillators


uk: Математика, природничі науки

uk: вхід без авторизації

name: Uncovering the mechanisms of self-organization behaviors in Myxococcus xanthus bacteria


uk: Математика, природничі науки

uk: вхід без авторизації

name: Computational Biomathematics Laboratory at Case Western Reserve University


uk: Математика, природничі науки

uk: вхід без авторизації

name: Boundary-driven emergent spatiotemporal order in growing microbial colonies


uk: Математика, природничі науки

uk: вхід без авторизації

name: Information processing in biological networks


uk: Математика, природничі науки

uk: вхід без авторизації

name: Molecular Communication: Analyzing Cell-Cell Interactions using Information Theory


uk: Математика, природничі науки

description: I will introduce some general properties of the generators mentioned in the title. This general properties will be illustrated in the case of low density type generators in the talk by Fernando Guerrero-Poblete.

uk: вхід без авторизації

name: Markov generators of stochastic limit type

name: Banff International Research Station (BIRS) for Mathematical Innovation and Discovery


uk: Математика, природничі науки

description: One of the main problems in statistical mechanics is the mathematical derivation, through space-time scaling limits, of macroscopic conservation laws, like compressible Euler equations or the heat equation, from the microscopic dynamics of molecules. Different space-time scalings, that we denote hydrodynamic limits, can lead to different macroscopic equations: the Euler system of equations governs the convergence to mechanical equilibrium (towards constant pressure) in a hyperbolic scaling, while at diffusive scaling (larger time) heat equation governs the convergence to thermal equilibrium (constant temperature), if thermal conductivity is finite. Deriving macroscopic limits from a deterministic (classical Hamiltonian or quantum) dynamics is a famous arduous problem. Some results can be obtained by adding to the dynamics some random terms such that momentum, energy and volume are still conserved but all other integrals of the motion are destroyed. The harmonic chain, despite the fact to be completely integrable, is an exception and, for the deterministic dynamics in thermal (global) equilibrium, the Euler equation are valid in the hyperbolic scaling. If the masses are random, thanks to Anderson localization, Euler equations are valid even out of thermal equilibrium. Furthermore, in the random mass case, the temperature profile remains constant in time at every later time scale, including the diffusive one, giving a further proof that thermal conductivity of this system is null. This results on the harmonic chain are extended to the corresponding quantum dynamics. (Works in collaboration with Cedric Bernardin, Francois Huveneers, Amirali Hannani)

uk: вхід без авторизації

name: Hydrodynamic limits from classical and quantum microscopic dynamics


Quantum Kac's chaos

uk: Математика, природничі науки

description: We study the notion of quantum Kac's chaos which was implicitly introduced by Spohn and explicitly formulated by Gottlieb. We prove the analogue of a result of Sznitman which gives the equivalence of Kac's chaos to 2-chaoticity and to convergence of empirical measures. Finally we give a simple, different proof of a result of Spohn which states that chaos propagates with respect to certain Hamiltonians that define the evolution of the mean field limit for interacting quantum systems. The talk is based on joint work with Rade Musulin.

uk: вхід без авторизації


uk: Математика, природничі науки

description: The class of Meixner random variables can be described in terms of a Lie Algebra structure generated by their quantum operators. This Lie Algebra structure is useful in computing first the kernels that give the second quantization operators, and then the Wick products generated by these random variables. We restrict our attention to three of the most important types of Meixner random variables: Gaussian, Poisson, and Gamma, and present some H ̈older inequalities for the norms of the Wick products generated by them. We show that these inequalities are related to sharp inequalities from classic Harmonic Analysis concerning the norms of some convolution-type products.

uk: вхід без авторизації

name: Hölder-type inequalities for norms of Wick products generated by a subclass of Meixner random variables


uk: Математика, природничі науки

description: In this talk the notion of circulant c.p. map will be extended to the Toeplitz case together with the usual technique of invariant subspaces in order to study the operator itself and its spectrum. Some results and simple cases will be reviewed. Finally, the relation between Toeplitz maps and a family of (non degenerate) WCLT generators will be described together with some simple results regarding the spectrum. This is a work in progress.

uk: вхід без авторизації

name: On the spectrum of completely positive Toeplitz Operators and Weak Coupling Limit type generators


uk: Математика, природничі науки

description: We will discuss on the general structure of the stationary states of excitation energy transport models and weak coupling limit type generators. Starting with the case of a non-degenerate reference Hamiltonian, we study the structure of stationary states belonging to the annihilator of all Krauss operators, including detailed balance and local detailed balance states. \\ (Joint work with \'Alvaro Hern\'andez-Cervantes)

uk: вхід без авторизації

name: Quantum energy transport models: structure of invariant states


uk: Математика, природничі науки

description: The mechanisms of quantum transport have attracted the attention of researchers from different areas (physics, chemistry, mathematics), who have produced an important amount of scientific, experimental or theoretical, work focused on describing and modeling these complex mechanisms. \\ Due to their characteristics as complex systems, semigroups of weak coupling limit type, with degenerate Hamiltonian, are suitable for modeling these phenomena. In this talk we will discuss the mathematical structure of the infinitesimal generator of some of these semigroups and the set of their stationary states. We will also present what is Free-Decoherence Algebra of a dynamic quantum semigroup of Markov, some characterizations of it and its application in the quantum transport model of [1]. \\ \\ \noindent{\bf References} \\ [1] Aref'eva, Y., Volovich, I. and Kozyrev, S. 2015. Stochastic Limit Method and Interference in Quantum Many-particles Systems. Theoretical and Mathematical Physics 183(3) (2015) 782-799

uk: вхід без авторизації

name: Some quantum transport models: stationary sates and the free decoherence algebra


uk: Математика, природничі науки

description: In recent years, digraph induced generators of quantum dynamical semigroups have been introduced and studied, particularly in the context of unique relaxation. In this talk we consider the converse construction to show every generator L naturally gives rise to a digraph GL. In specialized cases we use properties of GL to explicitly compute all invariant states of the semigroup. In the general case we discuss relaxation and the number of invariant states of the semigroup in terms of several other generator induced graphs.

uk: вхід без авторизації

name: Quantum Dynamical Semigroup Generator Induced Digraphs


uk: Математика, природничі науки

description: Attal and Joye (J. Funct. Anal. 247, 2007) studied a repeated-interactions model driven by particles in a faithful normal state. As they observed, the limit dynamics obey a Langevin equation driven by quantum noises which satisfy the commutation relations for a quasifree state. Inspired by this example, we describe a general framework to handle such quasifree random walks. The theory of quasifree quantum stochastic integration required to describe the limit cocycles builds on early work of Hudson and Lindsay, together with more recent work of Lindsay, Margetts and Weatherall.

uk: вхід без авторизації

name: From quantum random walks to quasifree stochastic cocycles


uk: Математика, природничі науки

description: D. Bures defined a metric on states of a C*-algebra as the infimum of the distance between associated vectors in common GNS representations. Now there are modifications and extensions of this notion to completely positive maps. We present some recent results in the area. This is based on joint works with K. Sumesh and Mithun Mukherjee.

uk: вхід без авторизації

name: Bures distance for completely positive maps


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Millions of people around the world are visually impaired or completely blind . This group audience need to cope with many challenges on a day-to-day basis, some of which are related to traveling and exploring the urban space. Since wayfinding is mainly constructed through the visual channel, blind pedestrians experience many unique challenges from the lack of information about the space they traverse, severely restricting their mobility and independence, impairing their quality of life. In this research, we examine the possibility of using OpenStreetMap to map geospatial data relevant to blind pedestrians. This data is then used to calculate optimized walking routes that satisfy their unique preferences and requirements. An in-depth investigation, observations, and interviews with Orientation and Mobility instructors, as well as with blind people, led to a clear definition of the spatial criteria that best reflect aspects of mobility, accessibility, and safety. These include, among others, the geometric complexity of the route, the type of the route, the existence of landmarks and traffic signals along the route. Controlled iterative experiments led to the definition of weighted graph criteria, used for the development of a route calculation software that recommends the optimized route for blind pedestrians. The developed software was tested for a number of routes with blind volunteers and Orientation and Mobility instructors. The results proved that not only the routes recommended by the software were identical to the routes defined by the experienced Orientation and Mobility instructor, but also the participants noted that in most cases the route chosen by the software was more accessible and safer to walk than the route calculated by a commercial software. The findings of this research indicate that this solution is effective and useful, utilizing OpenStreetMap for the benefit of blind people, which can improve their lives in terms of mobility, accessibility, and independence, assisting them to integrate into society.

uk: вхід без авторизації

name: Route Planning for Blind Pedestrians using OpenStreetMap


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: Come learn how Elastic uses administrative boundaries curated from OSM and Wikidata to visualize large data sets with Elasticsearch and Kibana.

uk: вхід без авторизації

name: Visualize large data sets with Elasticsearch and Kibana


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: We’ve finally gotten around to updating OHM with a variety of enhancements. This sessions will cover both (a) the tech upgrades & tradeoffs we’ve made to support a time slider and other time-dependent features, and (b) some content highlights.

uk: вхід без авторизації

name: Update on Open Historical Map: Using the OSM stack live with vector tiles


uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

de: Geowissenschaften (ohne Geographie)

uk: Науки про Землю(крім географії)

en: Geosciences (excl. Geography)

uk: Математика, природничі науки

uk: Гуманітарні науки

description: The Travel Mapping project (http://travelmapping,net) uses data derived from OSM and other sources to allow travel enthusiasts to track their cumulative travels on major highways. The Map-Based Educational Tools for Algorithm Learning (METAL, http://courses.teresco.org/metal) project uses this data for educational purposes, including an extensive interactive algorithm visualization system. This session will demonstrate both sides of this project.

uk: вхід без авторизації

name: Travel Mapping and METAL Maps and Map Data for Fun and Computer Science Education - Jim Teresco


Tracking Down SEO Contributers

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Науки про Землю(крім географії)

uk: Математика, природничі науки

uk: Гуманітарні науки

uk: вхід без авторизації


The serverless map stack lives

uk: Комп'ютерні науки

uk: Бібліотекознавство, документознавство

uk: Гуманітарні науки

description: The world of serverless technology is rapidly expanding. With the recent release of AWS Aurora Serverless for Postgres let’s find out if it’s now possible to build an entirely serverless map stack.

uk: вхід без авторизації