Risiko und Rücklagenmanagement

keywords:
Wissenschaftsmanagement
Bildungsmanagement
Risikomanagement
Rücklagenmanagement
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Бізнес та економіка

uk: Право, економіка та суспільні науки

description: In diesem Material werden die Grundlagen des Rücklagenmanagements vor dem Hintergrund finanzieller Risiken in der Hochschulfinanzierung erläutert. Prof. Ziegele geht nicht nur auf die Planung des Rücklagenmanagements, sondern zeigt auch auf, welche Risiken auftreten können und wie sich auf diese vorbereitet werden kann.

uk: вхід без авторизації


Frank Ziegele

type: Person

keywords:
Wissenschaftsmanagement
Bildungsmanagement
Hochschule Osnabrück
Diversifizierung
Finanzquellen
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

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: Dieses Screencast-Video beschäftigt sich mit der Frage, wieso die Diversifizierung von Finanzquellen an wissenschaftlichen Hochschulen in den letzten Jahren kontinuierlich angestiegen ist. Der Fokus liegt hierbei vor allem auf den unterschiedlichen Entwicklungen der Diversifizierung der Finanzquellen, weswegen jeweils auf die jeweiligen Entwicklungsarten eingegangen wird und diese anhand von Beispielen verdeutlicht werden.

TIB AV-Portal

type: Service

type: WebContent

type: MediaObject

@language: de

cs: přihlášení není vyžadováno

de: keine Anmeldung erforderlich

uk: вхід без авторизації

en: no login required

nl: geen login vereist

name: Diversifizierung der Finanzquellen steigt

Hochschule Osnabrück

addressCountry: DE

addressLocality: Osnabrück

addressRegion: Lower Saxony

type: Organization

cs: Video

de: Video

fi: Video

uk: Відео

en: Video

fr: Vidéo

da: Video

nl: Video

es: Video


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Hochschule Osnabrück
Diversifizierung
Finanzquellen
Finanzmanagement
Kosten- und Finanzmanagement
Kostenmanagement

uk: Бізнес та економіка

uk: Право, економіка та суспільні науки

description: In diesem Screencast-Video werden nicht nur die Herausforderungen diversifizierter Finanzquellen an Hochschulen dargestellt und an Beispielen verdeutlicht, sondern auch die Vorteile dieser Diversifizierung werden angesprochen und erläutert. Am Ende werden die aus der Diversifizierung hervorgehenden Aufgaben für das Wissenschaftsmanagement benannt, um so eine praktikable Handlungsempfehlung bieten zu können.

uk: вхід без авторизації

name: Herausforderungen durch die Diversifizierung von Finanzquellen


Gestaltung des Hochschulcontrollings

keywords:
Wissenschaftsmanagement
Bildungsmanagement
Hochschule Osnabrück
Akademisches Controlling
Controlling
Video
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Бізнес та економіка

uk: Право, економіка та суспільні науки

description: In diesem Screencast-Video geht Prof. Ziegele auf die Gestaltung des Hochschulcontrollings an deutschen Hochschulen ein. Er geht nicht nur auf Handlungsfelder und Grundüberlegungen des Hochschulcontrollings ein, sondern thematisiert auch Probleme innerhalb des Hochschulcontrollings sowie dessen aktuelle Tendenzen.

uk: вхід без авторизації


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Finanzmanagement
Kostenmanagement
Hochschulmanagement
Controlling
Hochschulcontrolling
Konzept NRW 2010

uk: Бізнес та економіка

uk: Право, економіка та суспільні науки

description: Im Screencast „Hochschulcontrolling am Beispiel NRW 2010“ zeigt Professor Ziegele anhand eines ausgewählten Beispiels des Konzeptes, wie Hochschulcontrolling nicht genutzt werden sollte. Dabei geht er darauf ein, welche Probleme entstehen, wenn man aus gemessenen Werten im Controlling automatische Entscheidungen ableitet, anstatt Zahlen zur Grundlage weitergehender Reflexionen zu machen.

uk: вхід без авторизації

name: Hochschulcontrolling am Beispiel Konzept NRW 2010


Elemente des akademischen Controllings

keywords:
Wissenschaftsmanagement
Bildungsmanagement
AkCont
Akademisches Controlling
Kostenmanagement
Finanzmanagement
Hochschulmanagement
Controlling

cs: Technické vědy

de: Ingenieurwissenschaften

fi: tekniikka

uk: Інженерія

en: Engineering Sciences

fr: Ingénierie

da: Ingeniørvidenskab

es: Ingeniería

nl: Engineering

uk: Бізнес та економіка

uk: Право, економіка та суспільні науки

description: Im Screencast „Elemente des Akademischen Controllings“ erläutert Professor Ziegele wie man einen Controlling Begriff im Hochschulkontext entwickeln kann und stellt eine erste Definition des Begriffs vor.

uk: вхід без авторизації


Bildung und Nutzung eines Zentralpools

keywords:
Wissenschaftsmanagement
Bildungsmanagement
Zentralpool
Kostenmanagement
Finanzmanagement
Kosten- und Finanzmanagement

uk: Бізнес та економіка

uk: Право, економіка та суспільні науки

description: Dieser Screencast ist die Lösung zur Aufgabe "Wie schafft man einen Zentralpool". Dabei wird erklärt, wie ein Zentralpool gebildet und genutzt werden kann. Zunächst wird die erste Frage beantwortet, wie ein Zentralpool gespeist wird. Anschließend wird die zweite Frage beantwortet, wie ein Zentralpool gestaltet werden kann.

uk: вхід без авторизації


Zentrale und dezentrale Budgetierung

keywords:
Wissenschaftsmanagement
Bildungsmanagement
Finanzmanagement
Globalbudgets
Finanzierungskompetenzen an Hochschulen
Budgetierungsmodell
Mittelvergabe
Kostenmanagement
Kosten- und Finanzmanagement

uk: Бізнес та економіка

uk: Право, економіка та суспільні науки

description: In diesem Material erklärt Professor Ziegele die Grundlagen der zentralen und dezentralen Budgetierung. Dabei werden die Vorteile einer zentralen Verteilung erläutert und anschließend die Vorteile einer dezentralen Verteilung verdeutlicht. Abschließend wird festgestellt, dass eine intelligente Mischung aus zentraler und dezentraler Budgetierung die beste Lösung darstellt.

uk: вхід без авторизації


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: We extend the hierarchical decomposition of an image as a sum of constituents of different scales, introduced by Tadmor, Nezzar and Vese in 2004, to a general setting. We develop a theory for multiscale decompositions which, besides extending the one of Tadmor, Nezzar and Vese to arbitrary L^2 functions, is applicable to nonlinear inverse problems, as well as to other imaging problems. As a significant example, we present applications to the inverse conductivity problem. This is a joint work with Klas Modin and Adrian Nachman.

@language: en

uk: вхід без авторизації

name: A multiscale approach for inverse problems

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


uk: Математика, природничі науки

description: The talk will discuss the homeland security problem of detecting presence of emission sources at high noise conditions. (Semi-)analytic and deep learning techniques will be compared. This is a joint work with W. Baines and J. Ragusa.

uk: вхід без авторизації

name: Detecting presence of low SNR emission sources Analysis and "analysis" vs deep learning


uk: Математика, природничі науки

description: We present some Lipschitz stability estimates for the Hausdorff distance of polygonal or polyhedral inclusions in terms of the Dirichlet-to-Neumann map based on a series of papers in collaboration with Elena Beretta (New York University AbuDhabi) and Sergio Vessella (Università di Firenze).

uk: вхід без авторизації

name: Stable determination of polygonal and polyhedral interfaces from boundary measurements


uk: Математика, природничі науки

description: In this talk I will discuss how ideas from applied harmonic analysis, in particular sampling theory and compressed sensing, may be applied to inverse problems for partial differential equations. The focus will be on inverse boundary value problems for the conductivity and the Schrodinger equations, but the approach is very general and allows to handle many other classes of inverse problems. I will discuss uniqueness, stability and reconstruction, both in the linearized and in the nonlinear case.

uk: вхід без авторизації

name: Infinite-dimensional inverse problems with finite measurements


uk: Математика, природничі науки

description: Diseases like cancer or arteriosclerosis often cause changes of tissue stiffness in the micrometer scale. Our work aims at developing a non-invasive method to quantitatively image these biomechanical changes and study the potential of the method for medical diagnostics. We focus on quantitative elastography combined with photoacoustic (PAT) and optical coherence tomography (OCT). The problem we deal with consists in estimating elastic material parameters from internal displacement data, which are evaluated from OCT-PAT recordered successive images of a sample.

uk: вхід без авторизації

name: Quantitative OCT-PAT Elastography for Biomechanical Parameter Imaging


uk: Математика, природничі науки

description: This talk addresses the solution of inverse problems in imaging given an additional reference image. We combine a modification of the discrete geodesic path model of Berkels, Effland and Rumpf with a variational model, actually the L 2 -T V model, for image restoration. We prove that the space continuous model has a minimizer and propose a minimization procedure which alternates over the involved sequences of deformations and images. The minimization with respect to the image sequence exploits recent algorithms from convex analysis to minimize the L 2 -T V functional. For the numerical computation we apply a finite difference approach on staggered grids together with a multilevel strategy. We present proof-of-the-concept numerical results for sparse and limited angle computerized tomography as well as for superresolution demonstrating the power of the method. Further we apply the morphing approach for image colorization.

uk: вхід без авторизації

name: Regularization of Inverse Problems via Metamorphosis along Geodesics in Image Spaces


Continuous Limits of Discrete Processes

uk: Математика, природничі науки

description: The possibility that a discrete process can be closely approximated by a continuous one, with the latter involving a differential system, is fascinating. Important theoretical insights, as well as significant computational efficiency gains may lie in store. A great success story in this regard are the Navier-Stokes equations, which model many phenomena in fluid flow rather well. Recent years saw many attempts to formulate more such continuous limits, and thus harvest theoretical and practical advantages, in diverse areas including mathematical biology, image processing, game theory, computational optimization, and machine learning. Caution must be applied as well, however. In fact, it is often the case that the given discrete process is richer in possibilities than its continuous differential system limit, and that a further study of the discrete process is practically rewarding. I will show two simple examples of this. Furthermore, there are situations where the continuous limit process may provide important qualitative, but not quantitative, information about the actual discrete process. I will demonstrate this as well and discuss consequences.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In this talk we will discuss a non-linear variant of Lavrentiev regularisation, where the sub-differential of the total variation replaces the identity operator as regularisation term. The advantage of this approach over Tikhonov based total variation regularisation is that it avoids the evaluation of the adjoint operator on the data. As a consequence, it can be used, for instance, for the solution of Volterra integral equations of the first kind, where the adjoint would require an integration forward in time, without the need of accessing future data points. We will discuss first the theoretical properties of this method, and then propose a taut-string based numerical method for the solution of one-dimensional problems.

uk: вхід без авторизації

name: Total variation based Lavrentiev regularisation


uk: Математика, природничі науки

description: The backwards heat equation is one of the classical inverse problems, related to a wide range of applications and exponentially ill-posed. One of the first and maybe most intuitive approaches to its stable numerical solution was that of quasireversibility, whereby the parabolic operator is replaced by a differential operator for which the backwards problem in time is well posed. After a short overview of approaches in this vein, we will dwell on a new one that relies on replacement of the first time derivative in the PDE by a fractional differential operator, which, due to the asymptotic properties of the Mittag-Leffler function as compared to the exponential function, leads to an only moderately ill-posed problem. Thus the order alpha of (fractional) differentiation acts as a regularization parameter and convergence takes place in the limit as alpha tends to one. We study the regularizing properties of this approach and a regularization parameter choice by the discrepancy principle. Additionally, a substantial numerical improvement can be achieved by exploiting the linearity of the problem by breaking the inversion into distinct frequency bands and using a different fractional order for each. This is joint work with William Rundell.

uk: вхід без авторизації

name: Regularization of backwards diffusion by fractional time derivatives


uk: Математика, природничі науки

description: Conditional stability estimates require additional regularization for obtaining stable approximate solutions if the validity area of such estimates is not completely known. The focus of this talk is on the Tikhonov regularization under conditional stability estimates for non-linear ill-posed problems in Hilbert scales, where the case that the penalty is oversmoothing plays a prominent role. This oversmoothing problem has been studied early for linear forward operators, most notably in the seminal paper by Natterer 1984. The a priori parameter choice used there, just providing order optimal convergence rates, has in the oversmoothing case the unexpected property that the quotient of the noise level square and the regularization parameter tends to infinity when the noise level tends to zero. We provide in this talk some new convergence rate results for nonlinear problems and moreover case studies that enlighten the interplay of conditional stability and regularization. In particular, there occur pitfalls for oversmoothing penalties, because convergence can completely fail and the stabilizing effect of conditional stability may be lost.

uk: вхід без авторизації

name: The impact of conditional stability estimates on variational regularization and the distinguished case of oversmoothing penalties


uk: Математика, природничі науки

description: We address two well known iterative regularization methods for ill-posed problems (Landweber and iterated-Tikhonov methods) and discuss how to improve the performance of these classical methods by using convex analysis tools. The talk is based on two recent articles (2018): Range-relaxed criteria for choosing the Lagrange multipliers in nonstationary iterated Tikhonov method (with R.Boiger, B.F.Svaiter), and On a family of gradient type projection methods for nonlinear ill-posed problems (with B.F.Svaiter)

uk: вхід без авторизації

name: A Projection Strategy for Choosing the Regularization Parameter of Iterated Tikhonov Method in Hilbert/Banach Spaces


Deep Neural Networks motivated by PDEs

uk: Математика, природничі науки

description: One of the most promising areas in artificial intelligence is deep learning, a form of machine learning that uses neural networks containing many hidden layers. Recent success has led to breakthroughs in applications such as speech and image recognition. However, more theoretical insight is needed to create a rigorous scientific basis for designing and training deep neural networks, increasing their scalability, and providing insight into their reasoning. This talk bridges the gap between partial differential equations (PDEs) and neural networks and presents a new mathematical paradigm that simplifies designing, training, and analyzing deep neural networks. It shows that training deep neural networks can be cast as a dynamic optimal control problem similar to path-planning and optimal mass transport. The talk outlines how this interpretation can improve the effectiveness of deep neural networks. First, the talk introduces new types of neural networks inspired by to parabolic, hyperbolic, and reaction-diffusion PDEs. Second, the talk outlines how to accelerate training by exploiting multi-scale structures or reversibility properties of the underlying PDEs. Finally, recent advances on efficient parametrizations and derivative-free training algorithms will be presented.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Deep Learning (DL) has become a pervasive approach in many machine learning tasks and in particular in image processing problems such as denoising, deblurring, inpainting and segmentation. The application of DL within inverse problems is less well explored because it is not trivial to include Physics based knowledge of the forward operator into what is usually a purely data-driven framework. In addition some inverse problems are at a scale much larger than image or video processing applications and may not have access to sufficiently large training sets. In this talk I will present some of our approaches for i) developing iterative algorithms combining data and knowledge driven methods with applications in medical image reconstruction ii) developing a learned PDE architecture for forward and inverse models of non-linear image flow. Joint work with : Marta Betcke, Andreas Hauptmann, Felix Lucka

uk: вхід без авторизації

name: Combining learned and model based approaches for inverse problems


uk: Математика, природничі науки

description: The reconstruction in quantitative coupled physics imaging often requires that the solutions of certain PDEs satisfy some non-zero constraints, such as the absence of critical points or nodal points. After a brief review of several methods used to construct such solutions, I will focus on a recent approach that combines the Runge approximation and the Whitney embedding theorem.

uk: вхід без авторизації

name: Combining the Runge approximation and the Whitney embedding theorem in hybrid imaging


uk: Математика, природничі науки

description: In this talk we discuss architectures for deep neural networks that preserve the energy of the propagated signal. We show that such networks can have significant computational advantages for some key problems in computer vision.

uk: вхід без авторизації

name: Fully Hyperbolic and Conservative Deep Neural Nets


uk: Математика, природничі науки

uk: вхід без авторизації

name: New results on a variational inequality formulation of Lavrentiev regularization for nonlinear monotone ill-posed problems


uk: Математика, природничі науки

description: The reconstruction of sparse signals from indirect, noisy data is a challenging inverse problem. In the Bayesian framework, the sparsity belief can be encoded via hierarchical prior models. In this talk we discuss the convexity - or lack thereof - of the functional associated to different models, and we show that Krylov subspace methods for the computation of the MAP solution implicitly perform an effective and efficient model reduction.

uk: вхід без авторизації

name: Bayesian hierarchical models: convexity, sparsity and model reduction


uk: Математика, природничі науки

description: The Ensemble Kalman filter (EnKF) has had enormous impact on the applied sciences since its introduction in the 1990s by Evensen and coworkers. It is used for both data assimilation problems, where the objective is to estimate a partially observed time-evolving system, and inverse problems, where the objective is to estimate a (typically distributed) parameter appearing in a differential equation. In this talk we will focus on the identification of parameters through observations of the response of the system - the inverse problem. The EnKF can be adapted to this setting by introducing artificial dynamics. Despite documented success as a solver for such inverse problems, there is very little analysis of the algorithm. In this talk, we will discuss well-posedness and convergence results of the EnKF based on the continuous time scaling limits, which allow to derive estimates on the long-time behavior of the EnKF and, hence, provide insights into the convergence properties of the algorithm. This is joint work with Dirk Bloemker (U Augsburg), Andrew M. Stuart (Caltech), Philipp Wacker (FAU Erlangen-Nuernberg) and Simon Weissmann (U Mannheim).

uk: вхід без авторизації

name: On the Analysis of the Ensemble Kalman Filter for Inverse Problems and the Incorporation of Constraints


uk: Математика, природничі науки

description: We generate reduced order Galerkin models for inversion of the Schr\"odinger equation given boundary data in the spectral domain for one and two dimensional problems. We show that in one dimension, after Lanczos orthogonalization, the Galerkin system is precisely the same as the three point staggered finite difference system on the corresponding spectrally matched grid. The orthogonalized basis functions depend only very weakly on the medium, and thus by embedding into the continuous problem, the reduced order model yields highly accurate internal solutions. In higher dimensions, the orthogonalized basis functions play the role of the grid steps, and highly accurate internal solutions are still obtained. We present inversion experiments based on the internal solutions in one and two dimensions. This is joint with: L. Borcea, V. Druskin, A. Mamonov, M. Zaslavsky.

uk: вхід без авторизації

name: Reduced order models for spectral domain inversion: Embedding into the continuous problem and generation of internal data


uk: Математика, природничі науки

description: We propose in this paper a novel two-stage projection correction modeling (PCM) framework for image reconstruction from (nonuniform) Fourier measurements. PCM consists of a projection stage (P-stage) motivated by the multiscale Galerkin method and a correction stage (C-stage) with an edge guided regularity fusing together the advantages of total variation and total fractional variation. The P-stage allows for continuous modeling of the underlying image of interest. The given measurements are projected onto a space in which the image is well represented. We then enhance the reconstruction result at the C-stage that minimizes an energy functional consisting of a delity in the transformed domain and a novel edge guided regularity. We further develop ecient proximal algorithms to solve the corresponding optimization problem. Various numerical results in both one-dimensional signals and two-dimensional images have also been presented to demonstrate the superior performance of the proposed two-stage method to other classical one-stage methods. This is a joint work with Yue Zhang (now at Siemens Corporate Research) and Guohui Song (Clarkson University).

uk: вхід без авторизації

name: PCM-TV-TFV: A Novel Two-Stage Framework for Image Reconstruction from Fourier Data

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


uk: Математика, природничі науки

description: In this presentation we will discuss recent progress in non-iterative methods in the time domain. The use of time dependent data is a remedy for the large spacial aperture that these method need to obtain a reasonable reconstructions. Fist we consider the linear sampling method for solving inverse scattering problem for inhomogeneous media. A fundamental tool for the justification of this method is the solvability of the time domain interior transmission problem that relies on understanding the location on the complex plane of transmission eigenvalues. We present our latest result on the solvability of this problem. As opposed to the frequency domain case, in the time domain there are no known qualitative methods with a complete mathematical justification, such as e.g. the factorization method.This is still a challenging open problem and the second part of the talk addresses this issue. In particular, we discuss the factorization method to obtain explicit characterization of a (possibly non-convex) Dirichlet scattering object from measurements of time-dependent causal scattered waves in the far field regime. In particular, we prove that far fields of solutions to the wave equation due to particularly modified incident waves, characterize the obstacle by a range criterion involving the square root of the time derivative of the corresponding far field operator. Our analysis makes essential use of a coercivity property of the solution of the Dirichlet initial boundary value problem for the wave equation in the Laplace domain that forces us to consider this particular modification of the far field operator. The latter in fact, can be chosen arbitrarily close to the true far field operator given in terms of physical measurements. Finally we discuss some related open questions.

uk: вхід без авторизації

name: Inverse Scattering Problems for the Time Dependent Wave Equation


uk: Математика, природничі науки

description: We tackle the reconstruction of discontinuous coefficients in a semilinear elliptic equation from the knowledge of the solution on the boundary of the planar bounded domain. The problem is motivated by an application in cardiac electrophysiology. We formulate a constraint minimization problem involving a quadratic mismatch functional enhanced with a phase field term which penalizes the perimeter. After computing the optimality conditions of the phase-field optimization problem and introducing a discrete finite element formulation, we propose an iterative algorithm and prove convergence properties. Several numerical results are reported, assessing the effectiveness and the robustness of the algorithm in identifying arbitrarily-shaped inclusions. (Joint work with E. Beretta and L. Ratti)

uk: вхід без авторизації

name: Detection of conductivity inclusions in a semilinear elliptic problem arising from cardiac electrophysiology


keywords:
Wissenschaftsmanagement
Bildungsmanagement
Hochschulfinanzierung
Zielvereinbarungen
Finanzierungsformel
Formelfinanzierung
Formelgebundene Finanzierung
Formel
Kosten- und Finanzmanagement
Kostenmanagement
Finanzmanagement

uk: Право, економіка та суспільні науки

description: In diesem Video beantwortet Prof. Dr. Frank Ziegele die Frage, welches Instrument der Hochschulfinanzierung besser geeignet ist, die Formel oder die Zielvereinbarung. Dabei zeigt er die verschiedenen Vor- und Nachteile beider Modelle auf. Schlussendlich wird gezeigt, dass die beste Möglichkeit eine Kombination beider Instrumente ist.

uk: вхід без авторизації

name: Was ist das bessere Instrument der Hochschulfinanzierung: Formeln oder Zielvereinbarung?


uk: Математика, природничі науки

description: Recent years have seen the introduction of various multi-field inflationary scenarios, in which the scalar curvature plays a crucial role. We outline a simple description that unifies these different proposals. Moreover, one can easily see which dynamical attractors will dominate the late-time behaviour of the system. We demonstrate which bifurcations govern the underlying dynamics.

uk: вхід без авторизації

name: Attractors, Bifurcations and Curvature in Multi-field Inflation


uk: Математика, природничі науки

description: Cosmological inflation predicts the existence of a stochastic background of gravitational waves, whose features depend on the model of inflation under consideration. There exist well motivated frameworks predicting an enhancement of the primordial gravity wave spectrum at frequency scales testable with gravitational wave experiments, with distinctive features as parity violation and non-Gaussianity. I will explain the properties of such scenarios, and their distinctive predictions for what respect the gravity wave power spectrum and bispectrum. I will then discuss how to quantitatively test these predictions with current and future interferometers.

uk: вхід без авторизації

name: Probing the Physics of the Early Universe with Gravitational Interferometers


Geometric inflation

uk: Математика, природничі науки

description: We argue that the presence of an inflationary epoch is a natural, almost unavoidable, consequence of the existence of a sensible effective action involving an infinite tower of higher-curvature corrections to the Einstein-Hilbert action. No additional fields besides the metric are required. This correction to General Relativity has the following features: (i) its vacuum spectrum solely consists of a graviton and is ghost free, (ii) it possesses well-behaved black hole solutions, (iii) its cosmology is well-posed as an initial value problem and, most importantly, (iv) it has the potential to provide a late-time cosmology arbitrarily close to LCDM while, at the same time, giving an inflationary period in the early universe with a graceful exit

uk: вхід без авторизації


uk: Математика, природничі науки

description: Effective field theory methods underpin quantum calculations with gravity, and thereby ensure the reliability of predictions for Hawking radiation or inflationary primordial fluctuations. Yet persistent concerns (like the phenomenon of secular growth in primordial fluctuations or information loss for Hawking radiation) appear to indicate a breakdown of these techniques in what ought to be a regime under good control. This talk argues that gravity indeed introduces new boundaries to the domain of validity of EFT methods, particularly at late times (where most of the puzzles seem to lie). Evidence for this picture is provided, together with remedies that come from other, more familiar, areas of physics where similar issues also arise.

uk: вхід без авторизації

name: Qubits in Space: Late-time evolution with Horizons


Recent Developments on String Cosmology

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

description: Non-perturbative effects were long ago proposed to be useful for supersymmetric moduli stabilization in Type II string theory compactifications. Their use has been widely studied from the 4D perspective but from the 10D perspective this mechanism is far from being understood. By performing a 10D analysis I will show several features of the mechanism, confirming some old 4D results as well as providing new properties of the compactification.

uk: вхід без авторизації

name: Non-perturbative effects and moduli estabilization from 10D


uk: Математика, природничі науки

description: We study how the presence of hierarchy on the moduli fields plays a determinant role for satisfying the recent Swampland criteria for some concrete examples.

uk: вхід без авторизації

name: Leaving the Swampland with non-geometric fluxes


uk: Математика, природничі науки

description: Inflation is a phase of accelerated expansion, taking place at very high energy in the early Universe. During this epoch, inhomogeneities are generated on cosmological scales from the amplification of quantum fluctuations of the gravitational and matter fields, that are stretched to distances of astrophysical interest today. The energy scales involved during this early epoch are many orders of magnitude greater than those accessible in particle physics experiments. The early Universe is thus one of the most promising probes to test far beyond standard model physics. When inflation is embedded in high-energy theories (supersymmetry, super-gravity, string theory, etc), different inflationary scenarios emerge that lead to different observational predictions. Those can be tested against high-precision measurements of the cosmic microwave background temperature and polarisation anisotropies. I will review the current status of the numerous proposed models, and highlight those for which the data show the strongest preference.

uk: вхід без авторизації

name: Constraining string-inspired inflationary models


T-dualities in GLSMs and geometry

uk: Математика, природничі науки

description: We explore the connection between mirror symmetry in non-complete intersection Calabi-Yau varieties and newly developed non- abelian dualities in their gauged linear sigma model descriptions.

uk: вхід без авторизації


uk: Математика, природничі науки

description: I will focus on the Swampland Distance Conjecture for which infinite distances in field space imply an infinite tower of states becoming exponentially light. We present new evidence for this conjecture in Calabi-Yau manifolds, by studying the monodromy transformations associated to the infinite distance singularities in the moduli space. This monodromy generates an infinite orbit within the spectrum of BPS states and allow us to classify the different types of infinite distance loci. We apply the results to the complex structure and Kahler moduli spaces of Type II and M/F-theory Calabi-Yau compactifications. I will also discuss the implications for Inflation, including alpha-attractor models.

uk: вхід без авторизації

name: Stringy Evidence and Implications of the Swampland Distance Conjecture


uk: Математика, природничі науки

description: I will focus on type IIB Fibre Inflation and discuss first the interplay between reheating and the production of axionic dark radiation after the end of inflation. I will then analyse the possibility to have a potentially dangerous geometrical destabilisation of ultra-light isocurvature modes.

uk: вхід без авторизації

name: Reheating and geometrical destabilisation in Fibre Inflation


The Landscape in the Sky

uk: Математика, природничі науки

description: Inflation can be thought of as a low energy process of an ultraviolet theory. It is therefore natural to expect that several degrees of freedom might constitute the inflationary dynamics. We will discuss how such multifield set-ups can leave signatures in the statistics of temperature and matter inhomogeneities, giving us observational access to the UV framework.

uk: вхід без авторизації


uk: Математика, природничі науки

uk: вхід без авторизації

name: String Theory and de Sitter vacua: a complicated affair


uk: Математика, природничі науки

description: I will briefly review the issues of de Sitter vacua in string theory in relation to the various swampland conjectures which suggest a tension between an effective description of universe in accelerated expansion and its possible unitary UV completion. Subsequently I will address this UV/IR puzzle within the specific context of massive type IIA compactifications and discuss the status of the search for classical de Sitter solutions arising from reductions on SU(3) structure manifolds. I will then conclude by discussing the controversial issue of defining a good weakly coupled regime for such backgrounds.

uk: вхід без авторизації

name: Weakly coupled de Sitter in massive IIA compactifications?


uk: Математика, природничі науки

description: We construct models with U(1) gauge group and matter with charges up to 6, in the context of type IIB compactifications. We show explicitly that models with charges up to 4 can be derived from corresponding models in F-theory by applying the Sen weak coupling limit. We derive which type IIB models should be the limit of charge 5 and 6 F-theory models. Explicit six dimensional type IIB models with maximal charge 5 and 6 are constructed on an algebraic K3 surface that is the double cover of CP2. By using type IIB results we are also able to rediscover the F-theory charge 4 model in a straightforward way.

uk: вхід без авторизації

name: High U(1) Charge Models in type IIB and their F-Theory Lift


uk: Математика, природничі науки

uk: вхід без авторизації

name: Axion Experiments for String Compactifications


The Axidental Universe

uk: Математика, природничі науки

description: Theories with several hundred axion fields have enormous numbers of distinct meta-stable minima. A small fraction of these local minima have vacuum energy compatible with current measurements of dark energy. The potential also contains regions suitable for inflation, and gives rise to a natural type of dark matter. First-order phase transitions from one minimum to the vicinity of another play the role of big bangs and produce many bubbles containing evolving Friedmann-Lemaitre-Robertson-Walker universes. The great majority either collapse in a tiny fraction of a second, or expand exponentially forever as empty, structureless universes. However, restricting to those bubble universes that form non-linear structure at some time in their history we find cosmologies that look remarkably similar to ours. They undergo about 60 efolds of inflation, making them flat, homogeneous and isotropic, and endowing them with a nearly scale-invariant spectrum of primordial density perturbations with roughly the observed magnitude and tilt. They reheat after inflation to a period of radiation domination, followed by matter domination with roughly the observed abundance, followed by vacuum energy domination at roughly the observed density. None of these features require any model building or small parameters. Instead, all dimensionful parameters in the theory can be set equal to the grand unified scale 0.01 M_p, and the dimensionless parameters are order one and can be chosen randomly. The small value of dark energy ultimately comes from non-perturbative gravitational effects, giving an exponentially small vacuum energy density. Therefore, random axion landscapes can account for many of the apparently tuned features of our universe, including its current enormous size, age, and tiny energy densities compared to the scales of fundamental physics.

uk: вхід без авторизації


Machine Learning for string vacua

uk: Математика, природничі науки

description: In string theory, we face a gigantic number of backgrounds, each of which comes with different implications for particle physics and cosmology. On top of this, every backgrounds has a huge number of possible vacua or near-vacua. We describe the computational complexity of the challenges associated with both finding a viable background and finding vacua for this background, and apply machine learning to study a small subset of them.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Compactifications of string theory with geometric and non-geometric fluxes give rise to effective field theories with non-trivial scalar potentials, which can be used for moduli stabilization and cosmology. In this talk I briefly review such flux compactifications, emphasize various consistency conditions, and report on preliminary new results on the distribution of flux vacua.

uk: вхід без авторизації

name: (Non-)geometric fluxes and their applications


uk: Математика, природничі науки

description: We show how the Wess-Zumino terms of the different branes in string theory can be embedded within Double Field Theory. Crucial ingredients in our construction are the identification of the correct brane charge tensors and using the Double Field Theory potentials that arise from dualizing the standard Double Field Theory fields. This leads to a picture where under T-duality the brane does not change its worldvolume directions but where instead it shows different faces depending on whether some of the worldvolume and/or transverse directions invade the winding space.

uk: вхід без авторизації

name: The different faces of branes in Double Field Theory

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


Patterns in Crime: An Overview

uk: Математика, природничі науки

uk: вхід без авторизації


The Structure of Criminological Theory

uk: Математика, природничі науки

description: Criminology over the past 100 years can be criticized in general for barely increasing our ability to explain crime. However, this general criticism glosses over significant differences between what Robert Merton identified as low-, middle and high-range theories. Low-range theories are can be described as 'empirical laws', while high-range theories are are grand unifying concepts. Middle-range theories are principles--perhaps law-like statements in themselves--that aggregate empirical laws and are subsumed by high-range theories. This paper surveys explanation at each of these levels and argues that we do quite well with explanation at the scale of empirical laws, but still struggle with grand unifying concepts. Mathematics has the greatest potential to contribute in framing middle-range theory, which we can hope will make high-range theory more tractable.

uk: вхід без авторизації


uk: Математика, природничі науки

description: In this talk I will describe what agent-based models (ABMs) are and the mathematical challenges they present. I will also introduce data assimilation and the ensemble Kalman filter (EnKF). Using an extremely simple ABM, corresponding to a Markov chain that can be solved exactly, I will illustrate how the EnKF works and highlight some of things one must consider when applying data assimilation techniques. I will discuss an application using real data of footfall counts in Leeds.

uk: вхід без авторизації

name: Agent-based models and data assimilation


Self-Exciting Point Processes for Crime

uk: Математика, природничі науки

uk: вхід без авторизації


Exciting Adventures in Crime Linkage

uk: Математика, природничі науки

description: We present a model to predict spatial hotspots, defined as the regions in a future time period that have the highest proportion of events of interest. We assume the conditional intensity of the events of interest can be influenced by geospatial and temporal predictors as well as nearby events from other point processes, a common assumption in crime and conflict processes. Likewise, our model explicitly incorporates the characteristics of the spatial environment, temporal trends, and estimates the influence of past events. As a variation on traditional self-exciting (Hawkes) point process models, we directly model the probability that a location will be a member of the hotspot in a future time period. We use a penalized logistic regression model that allows the spatial covariates and each event type to have a different effect (including inhibition) on the probability. The duration of an event's influence is modeled by a mixture of decay functions resulting in a flexible and interpretable dependence structure.

uk: вхід без авторизації


uk: Математика, природничі науки

description: Crimes emerge out of complex interactions of behaviors and situations; thus there are complex linkages between crime incidents. Solving the puzzle of crime linkage is a highly challenging task because we often only have limited information from indirect observations such as records, text descriptions, and associated time and locations. We propose a new modeling and learning framework for detecting linkage between crime events using spatio-temporal-textual data, which are highly prevalent in the form of police reports. We capture the notion of modus operandi (M.O.), by introducing a multivariate marked point process and handling the complex text jointly with the time and location. The model is able to discover the latent space that links the crime series. The model fitting is achieved by a computationally efficient Expectation-Maximization (EM) algorithm. In addition, we explicitly reduce the bias in the text documents in our algorithm. Our numerical results using real data from the Atlanta Police show that our method has competitive performance relative to the state-of-the-art. Our results, including variable selection, are highly interpretable and may bring insights into M.O. extraction. This is a joint work with Shixiang Zhu at Georgia Tech.

uk: вхід без авторизації

name: Network Hawkes processes for crime events Change detection, text, and generative model


uk: Математика, природничі науки

description: We develop a sequential data assimilation algorithm for count data modelled by a doubly stochastic Poisson process. We apply an approximation technique similar to the extended Kalman filter to develop a sub-optimal discrete-time filtering algorithm, called the extended Poisson-Kalman lter (ExPKF), where only the mean and covariance are sequentially updated using count data via the Poisson likelihood function. The ExPKF, however, is inconvenient to use when the calculation of the Hessian is difficult. Thus, we also develop an ensemble-based filter based on the Gamma prior assumption; hence, ensemble Poisson-Gamma filter (EnPGF). The implementation of EnPGF is performed in the same manner as the serial-update version of EnKF. The performances of ExPKF and EnPGF are demonstrated in several synthetic experiments where the true solution is known. For the application to real-world data, we use ExPKF to approximate the uncertainty of urban crime intensity and parameters for Hawkes process and highlight the advantage of filtering scheme (over the non-filtering scheme) to track parameter changes.

uk: вхід без авторизації

name: Approximate filtering of intensity process for Poisson count data


uk: Математика, природничі науки

uk: вхід без авторизації

name: Predicting crime is easy, using crime predictions is hard


uk: Математика, природничі науки

description: Applications such as police body-worn video cameras generate a huge amount of data, beyond what is humanly possible for analysts to review. Such problems are ripe for the development of semi-supervised learning algorithms, which, by definition, use a small amount of training data. We introduce an uncertainty quantification (UQ) method for graph-based semi-supervised multi-class classification problems. We not only predict the class label for each data point but also provide a confidence score for the prediction. We adopt a Bayesian approach and propose a graphical multi-class probit model together with an effective Gibbs sampling procedure. Furthermore, we propose a confidence measure for each data point that correlates with the classification performance. We use the empirical properties of the proposed confidence measure to guide the design of a human-in-the-loop system. The uncertainty quantification algorithm and the human-in-the-loop system are successfully applied to classification problems in image processing and ego-motion analysis of body-worn videos.

uk: вхід без авторизації

name: Uncertainty Quantification for Semi-Supervised Multi-class Classification in Ego-Motion Analysis of Body-Worn Videos


Modelling Riot Dynamics

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

description: We investigate an SIRS epidemic PDE system with nonlinear incident rates. In the limit of small diffusion rate of infected class D_I, and on a finite interval, an equilibrium spike solution (or epidemic hotspot) to the epidemic model is constructed asymptotically and the motion of the spike is studied. For sufficiently large diffusion rate of recovered class D_R, the interior spike is shown to be stable, however it becomes unstable and moves to the boundary when $D_R$ is sufficiently small. We also studied two types of bifurcation behavior of multi-spike solutions: self-replication and spike competition, and their stability thresholds are precisely computed by asymptotic analysis and verified by numerical experiments. Finally, we show that the spike-type solution can transition into an interface-type solutions when the diffusion rates of recovered and susceptible class are sufficiently small, and the transition regime is obtained precisely.

uk: вхід без авторизації

name: Existence and stability of spike solution in SIRS model with diffusion


uk: Математика, природничі науки

description: Most approaches to the modelling of crime - for predictive purposes or otherwise - are situated in continuous space; most commonly continuous 2D space or a simple grid system. The true structure of urban space, however, is substantially more complex than this, with both the natural and built environment playing a key role in its configuration. A fundamental determinant of this structure is the street network, which governs both the locations of places and the paths between them. Empirical research has established not only that crime risk varies according to the structural (i.e. graph-theoretic) characteristics of streets, but that dynamic crime phenomena such as clustering can also be observed at the street network level. This evidence, as well as a number of conceptual concerns, suggests that the street network may constitute a more meaningful, or effective, substrate for models of crime. Initial research in this area using statistical models indeed suggests that the use of the street network can improve the predictive performance of crime models, producing outputs which can be readily acted upon by police forces. Nevertheless, there have been few attempts to use such representations of space in the context of more formal mathematical models. This talk will outline the state of evidence in this area, demonstrate some network-based approaches, and suggest opportunities for ongoing research.

uk: вхід без авторизації

name: Street networks and their role in crime modelling


uk: Математика, природничі науки

description: Natural disasters have been posed a significant threat in many areas of the United States. Many catastrophic ones had taken the lives of millions of people throughout history and caused severe negative economic damages. For example, known as Hurricane Harvey, the tropical storm had brought the loss of more than 125 billion dollars in the U.S.A. in 2017. It also claimed at least 107 people’s lives during the period, displaced 30,000 people, and prompted more than 17,000 rescues [2]. However, some safety preparations can be made in advance to mitigate the potential damages and reduce the loss. Accurate prediction for natural disaster hotspots and timely rescue resource allocation are two primary precautions to send out the help before major destructive events strike the targeted area. Through monitoring the past events, we can strategically make the decision of where we should deploy the rescue team beforehand or announce an early evacuation warning. Such a prediction task can be considered as a reinforcement learning process while we make the decisions based on the reward from our past actions. We further formulate our decision-making problem as a multi-arm bandit (MAB) problem. We first consider every region in the disaster-stricken area as an arm of a multi-armed bandit machine. In every time period, by “pulling the arms,” we observe the number of the disaster events of interest in only a couple of regions and we decide the regions to be observed in the next time period based on the past limited observations. We propose a MAB strategy that considers the tradeoff between the exploration for overlooked places while exploiting the regions with high event intensity. Our strategy combines the traditional epsilon-greedy algorithm that allows us to probe the uncharted area with non-parametric Hawkes process to capture the temporal dynamics in those well-observed regions [4]. Several MAB algorithms are compared with our proposed model [3]. Specifically, we gather the dataset from city requests for service that is reported in Houston, Texas during the time period of tropical storm Harvey [1]. Flooding events are extracted as the natural disaster of interest. Our model and other baselines are further evaluated by the recall of flooding events throughout the recorded timespan of Hurricane Harvey. The proposed model has an improvement of 36.38% compared to the best baseline model. The improvement shows that our proposed model can not only exploit the best available options where there is a high probability of flooding, but it also can gather more information in those overlooked places. In our future work, more timely relevant information, such as tweets from Twitter and the water level record from observations nearby the river and ocean, will be integrated into our model to make predictions more accurate.

uk: вхід без авторизації

name: Multi-armed bandit problem on rescue resource allocation


Visualization in Machine Learning

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

uk: вхід без авторизації

name: International Council for Scientific and Technical Information (ICSTI)


uk: Математика, природничі науки

description: I will discuss recent progress towards the Harish-Chandra classification for simple modules in category $\mathcal{O}$ of rational Cherednik algebras, and in particular discuss the extent to which Hecke algebras know the answer to the problem. Based on joint work with D. Juteau.

uk: вхід без авторизації

name: Harish-Chandra series for rational Cherednik algebras


uk: Математика, природничі науки

description: In this talk I will review the program of categorification of Verma modules of symmetrizable quantum Kac-Moody algebras and extend it to a categorification of tensor products of a Verma module and several integrable irreducibles. In the last part of the talk I will consider the case of $\mathfrak{sl}(2)$ and explain how its categorifications are endowed with an action of the Temperley-Lieb algebra of type B with two parameters. The material presented is based upon several collaborations with Grégoire Naisse, Ruslan Maksimau and Abel Lacabanne.

uk: вхід без авторизації

name: Categorification of Verma Modules, tensor products and the Temperley-Lieb algebra


uk: Математика, природничі науки

description: The Alexander polynomial for knots and links can be interpreted as a quantum knot invariant associated with the quantum group of the Lie superalgebra \mathfrak{gl}(1|1). This polynomial has been famously categorified to a link homology theory, knot Floer homology, defined within the theory of Heegaard-Floer homology. Andy Manion showed that the Ozsvath-Szabo algebras used to efficiently compute knot Floer homology categorify certain tensor products of \mathfrak{gl}(1|1) representations. For representation theorists, the work of Sartori provides a different categorification of these same tensors products using subquotients of BGG category \mathcal{O}. In this talk we will explain joint work with Andy Manion establishing a direct relationship between these two constructions. Given the radically different nature of these two constructions, transporting ideas between them provides a new perspective and allows for new results that would not have been apparent otherwise.

uk: вхід без авторизації

name: Bordered Heegaard-Floer homology, category O, and higher representation theory


uk: Математика, природничі науки

description: Back in 2004, Rasmussen extracted a numerical invariant from Khovanov-Lee homology, and used it to give a new proof of Milnor's conjecture about the slice genus of torus knots. In this talk, I will describe a generalization of Rasmussen's invariant to null-homologous links in connected sums of ^1 \times ^2. For certain links in ^1 \times ^2, we compute the invariant by reinterpreting it in terms of Hochschild homology. As applications, we prove inequalities relating the Rasmussen-type invariant to the genus of null-homologous surfaces with boundary in the following four-manifolds: B^2 \times ^2, ^1 \times B^3, CP^2, and various connected sums and boundary sums of these. We deduce that Rasmussen's invariant also gives genus bounds for surfaces inside homotopy 4-balls obtained from B^4 by Gluck twists. Therefore, it cannot be used to prove that such homotopy 4-balls are non-standard. This is based on joint work with Marco Marengon, Sucharit Sarkar, and Mike Willis.

uk: вхід без авторизації

name: Khovanov homology and surfaces in some 4-manifolds


uk: Математика, природничі науки

description: In this series of two talks we will explain the current state of the art concerning the problem of classifying "simple" 2-representations of Soergel bimodules. The first talk will introduce the asymtotic Hecke algebra and the asymptotic bicategory as well as their relationship. In particular, the asymptotic bicategories are well-understood in many cases, and this will be explained.

uk: вхід без авторизації

name: 2-representations of Soergel bimodules I


uk: Математика, природничі науки

description: This is the sequel to the talk of Daniel Tubbenhauer. The second part will explain the 2-representation theoretic ingredients to reduce a classification of simple transitive 2-representations of Soergel bimodules in many (most) cases to the known classification of simple transitive 2-representations of the corresponding asymptotic bicategory.

uk: вхід без авторизації

name: 2-representations of Soergel bimodules II


uk: Математика, природничі науки

description: The geometric Satake correspondence provides a beautiful geometric description of the representations of reductive groups, using the affine Grassmannian. In order to categorify this description, we use truncated shifted Yangians which quantize slices in the affine Grassmannian. Last year, we proved that category O for a truncated shifted Yangian is equivalent to a category of modules for a Khovanov-Lauda-Rouquier-Webster algebra. In this way, we obtain a categorical action on category Os for truncated shifted Yangians.

uk: вхід без авторизації

name: Categorification via truncated shifted Yangians


uk: Математика, природничі науки

description: One of the upshots of categorification constructions in representation theory is a nice stock of examples of actions of groups (e.g. braid groups) on triangulated categories. The goal of this talk will be to explain how, following an analogy with the study of mapping class groups of surfaces via Teichmuller theory, such categorical constructions can be used to study the groups themselves.

uk: вхід без авторизації

name: Categorification and geometric group theory

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


uk: Математика, природничі науки

description: Coulomb branches have recently been given a good mathematical footing thanks to work of Braverman-Finkelberg-Nakajima. We will discuss their categorical structure. For concreteness we focus on the massless case which leads us to the category of coherent sheaves on the affine Grassmannian (the so called coherent Satake category). This category is conjecturally governed by a cluster algebra structure. We will describe a solution to this conjecture in the case of general linear groups and discuss extensions of this result to more general Coulomb branches of 4D N=2 gauge theories. This is joint work with Harold Williams.

uk: вхід без авторизації

name: Categorical structure of Coulomb branches of 4D N=2 gauge theories


Flow lattices and Koszul algebras

uk: Математика, природничі науки

description: We define "q-cut" and "q-flow" lattices associated to a finite graph, arising from a categorification construction for the lattices of integer cuts and flows (which we'll introduce in the talk). We'll describe combinatorial properties of these invariants, including categorified/q-versions of some classical theorems in graph theory. Based on joint work with Tony Licata.

uk: вхід без авторизації


uk: Математика, природничі науки

description: I will define what is an abelian envelope of a fixed rigid symmetric monoidal category, in the sense of Deligne. I will also give several examples and applications, both in characteristic zero and in positive characteristic.

uk: вхід без авторизації

name: Abelian envelopes of rigid symmetric monoidal categories


Ringel duality for Soergel bimodules

uk: Математика, природничі науки

description: The category of Soergel bimodules is a well-behaved categorification of the Hecke algebra of a Coxeter group. In many characteristic 0 realizations, the indecomposable objects in this category correspond to the Kazhdan-Lusztig basis, thereby giving an explanation for the positivity of Kazhdan-Lusztig polynomials. In characteristic $p>0$ the indecomposable objects give rise to another set of non-negative Laurent polynomials called $p$-Kazhdan-Lusztig polynomials, which can be used as a replacement for Kazhdan-Lusztig polynomials in modular representation theory. In this talk I will propose a non-negative replacement for inverse Kazhdan-Lusztig polynomials in positive characteristic.

uk: вхід без авторизації


keywords:
fachfremd Unterrichten
Chemie
Demonstrationsexperiment

de: Chemie

fi: kemia

uk: Хімія

en: Chemistry

fr: Chimie

da: Kemi

es: Química

nl: Scheikunde

uk: Математика, природничі науки

uk: вхід без авторизації

name: Demonstrationsexperimente sicher und gut wahrnehmbar präsentieren

Europa-Universität Flensburg (EUF)

addressLocality: Flensburg

addressRegion: Schleswig-Holstein

name: Institut für mathematische, naturwissenschaftliche und technische Bildung


Elefantenzahnpasta

keywords:
fachfremd Unterrichten
Chemie
Experiment
Demonstrationsexperiment
Redoxreaktion
Katalysator
Sauerstoff
Iod

uk: Математика, природничі науки

uk: вхід без авторизації


Fettexplosion - Der Brand in der Küche

keywords:
fachfremd Unterrichten
Chemie
Experiment
Demonstrationsexperiment
exotherm
Löschen

uk: Математика, природничі науки

uk: вхід без авторизації


keywords:
fachfremd Unterrichten
Chemie
Experiment
exotherm
chemische Reaktion
Demonstrationsexperiment
Zeitlupe
Redoxreaktion
digitale Medien

uk: Математика, природничі науки

uk: вхід без авторизації

name: Wunderkerzen unter Wasser (auch in Slow-Motion)


Coastal Filters: The Farmer and the Sea

de: Biologie

uk: Біологія

en: Biology

uk: Математика, природничі науки

uk: вхід без авторизації

name: Max-Planck-Institut für Marine Mikrobiologie (MPI)


Das digitalisierte Korallenriff

uk: Математика, природничі науки

uk: вхід без авторизації


Digitizing the Coral Reef

uk: Математика, природничі науки

uk: вхід без авторизації


Küsten als Filter

uk: Математика, природничі науки

uk: вхід без авторизації


uk: Математика, природничі науки

description: Robotic design involves modeling the behavior of a robot mechanism when it moves along potential paths set by the users. In this lecture, we will first give an overview of different approaches to design a set of kinematic equations associated with a robot mechanism. In particular, these equations can be used to solve the forward and the backward kinematics problems associated with a robot mechanism or to model its singularity locus. Then we will review methods to solve those equations, and notably methods to draw with guarantees the real solutions of an under-constrained system of equations modeling the singularities of a robot.

uk: вхід без авторизації

name: Computational real algebraic geometry and applications to robotics - lecture 1

name: Centre International de Rencontres Mathématiques (CIRM)

addressCountry: FR

addressLocality: Marseille

addressRegion: Provence-Alpes-Côte d'Azur


uk: Математика, природничі науки

uk: вхід без авторизації

name: Die Rolle des Meeresbodens im Kohlenstoffkreislauf - Tiefseeroboter im Einsatz


uk: Математика, природничі науки

uk: вхід без авторизації

name: Lighting a lighter without oxygen: How deep-sea microbes live on natural gas


Titrationen mit digitalen Messsensoren

keywords:
fachfremd Unterrichten
Chemie
Experiment
Säure-Base-Reaktion
Redoxreaktion
Titration
Schüler:innenversuch
digitale Medien
digitale Messsensoren

uk: Математика, природничі науки

uk: вхід без авторизації


keywords:
fachfremd Unterrichten
Chemie
Experiment
Kalibrieren
digitale Messsensoren
digitale Medien
Titration
Säure-Base-Reaktion
Redoxreaktion
Schüler:innenversuch

uk: Математика, природничі науки

uk: вхід без авторизації

name: Kalibrieren eines digitalen Tropfenzählers


A new hope for migrations and upgrades

uk: Комп'ютерні науки

description: I've often argued for in-place migrations and worked hard to make them as easy as possible. The thing is: They are still hard. Especially when you add Archetypes/Dexterity, Python 2/3, Multilingual, old Add-ons and Volto to the hurdles to overcome. All of this changed when early this year a new star was born. It has started as the idea to build a small wrapper around serializing and deserializing content using the REST-Api. Since then collective.exportimport has grown into a powerfull tool with a beginner-friendly user-interface. I will show how it is used for all kinds of small and large migrations and how it can solve even the edgiest edge-cases.

uk: вхід без авторизації


A sustainable web: is it possible?

uk: Комп'ютерні науки

description: How much do we know about the impact of technologies we use everyday? How much the web industry is responsible for carbon emissions? Can we define an ethic development? I wrote the Sustainable Web Manifest and I'll tell you what does it mean. We'll look to the things that need to be fixed and the process to make a sustainable website. Finally, I’ll introduce an introspection in Volto issues and the future works as the result of my analysis.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Addon that uses Volto Slate plugin, to allow users to make citations by referencing documents in Zotero library and OpenAire.

uk: вхід без авторизації

name: Advanced Citations with Zotero and OpenAire in Plone 6


Automatic focal points for images

uk: Комп'ютерні науки

description: This is the tastiest presentation of the Plone conference! A customer of Zest has images of delicious cakes, bread, cookies. But a cropped version of such an image often does not show the yummy cake, but a blurred cup of tea in the background. Solution: automatic focal point detection. We could use a smart imaging service like Thumbor. But the latest alpha release with Python 3 support is one and a half years old. The part that actually detects the focal points is opencv, with help from numpy. Can we call this directly instead? Yes we can. Can we do this from within Plone? Yes, but we need a patch. In this talk, to refresh our memories, we will first look at what the various scale modes/directions do in Plone. Since the 'down' direction or 'contain' mode is the only one that actually does image cropping, we will focus on that. We will go through the code of the focal point detection, and show the result. Lastly, we will look at an idea to make image handling in Plone more pluggable, using a transform chain.

uk: вхід без авторизації


Automation power for Plone with n8n

uk: Комп'ютерні науки

description: n8n is a free and open workflow automation tool which teams up very nicely with Plone In this talk, I will demonstrate with some real-live examples how you can combine the power of n8n with the flexibility of the Plone Rest API: Create, update or delete any Plone content or user action automatically from any number of your favorite external tools like Trello, Google sheets, Facebook, Slack and many more. Once you have a basic setup, it is easy even for non-developers to create new automation workflows which are triggered from third-party tools to perform actions in your Plone site.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: collective.exportimport is the latest addition to our migration toolbox and we have achieved good results with it with upgrading Plone sites to Plone 5.2. But A new 'side' use case with this add-on getting mature is distributing content trees between existing Plone sites. For example to create an online marketing campaign and deploying the setup to several country sites for translation and local use. I will demonstrate the 'content copy' use case, discuss current state and planned/wished improvements. As a related subtopic I will also touch on current capabilities and 'caveats' of exportimport when using this for migrations based on our current experience.

uk: вхід без авторизації

name: collective.exportimport: tips, tricks and deploying staging content


uk: Комп'ютерні науки

description: - Andrei: World Plone Day 2022, - Hard: collective.fullcalendar, - McFadden: The Many Layers of Radio Free Asia, - Loechel: Regulation (EU) 2018/1724, - Nguyen: Plone in a Box™, - Aquino: UseCase - Plone in the Brazilian Superior Electoral Court, - Rees: Image transform chain, - Hendryx-Parker: Pyenv rocks and you should be using it, - Grunewald: Keeping track of your Plone customization - a little helper

uk: вхід без авторизації

name: Plone Conference 2021 - Day 2 Lightning Talks


uk: Комп'ютерні науки

description: - Holzer: My first Plone 6 site, - McFadden: Web developer confessions, - Casali: Plone sponsorships, - Jay: Why Drupal won down under, - Derstappen: Current state of Mockup, - Raggam: Javascript integration, - Glick: Snowfakery, - Bauer: One small VS Code trick, - Andrei: New Docker images

uk: вхід без авторизації

name: Plone Conference 2021 - Day 3 Lightning Talks


EEA Searchlib

uk: Комп'ютерні науки

description: Searchlib is an extensible library and associated applications that integrates ElasticSearch and NLP technologies to build an improve faceted search interface for data catalogues.

uk: вхід без авторизації


Efficient Backend development for Plone

uk: Комп'ютерні науки

description: Learn how to efficiently develop Plone addon's with "plonecli" and plugins for VS Code. Create Dexterity content types, views, behaviors, rest-api services and Classic-UI themes, to ramp up your plone backend in no-time.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: The talk will be separated on three parts: - Guillotina: At Flaps we developed all our data layer using Guillotina with an amazing result. We will explain our experience of how we used it and the pros and the cons of it. - FlapsDB: A new storage layer to allow AI search capabilities plus standard search. - Flaps: Our open source plan and how we want to help OSS projects like Plone and Guillotina to deliver more value.

uk: вхід без авторизації

name: Flaps: Build an AI-powered search engine for unstructured data with Flaps API


Forging a New Installer

uk: Комп'ютерні науки

description: Lets forge a new installer. The old one is rusty. These days we have pip, Python is standard on most systems and a JavaScript environment is nothing that scares administrators away anymore. Containers are state of the art, but not everywhere. Simplification on one hand comes with more requirements on the other hand. We started a new way of installing Plone, we have plans. Learn about our idea! And we need help and more input.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: What happened after a transition from a public institution to a international career restart in the middle of a pandemic.

uk: вхід без авторизації

name: From the longest project of my life to the toughest moment of my life.


uk: Комп'ютерні науки

description: There exist multiple Guillotina's add-ons that, out of the box, help us to build applications easily and faster than other frameworks. In this talk, I am going to explain how the elasticsearch, stripe and gcloud add-ons are integrated with guillotina, and how to use them in our application.

uk: вхід без авторизації

name: Guillotina Addons: elastic, stripe, gcloud


Guillotina React

uk: Комп'ютерні науки

description: Guillotina React is an application that allows manage Guillotina data on web. We explain how we can integrate with Guillotina and how we can configure it in different projects.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: The Helmholtz Association is Germany's biggest scientific organization including 18 research centers and over 40.000 employees. To digitally connect every employee even though they work in different places with different infrastructures HIFIS (Helmholtz Federated IT Services) has been brought to life. HIFIS brings powerful IT infrastructure and Services to all research centers. To assemble a wide cluster of IT Services, they asked for help to allow Helmholtz members to register their services in the HIFIS Cloud. In collaboration with HZB (Helmholtz Center Berlin) and kitconcept, Plone was chosen to fill that gap and to create a platform that allows users to register those Services. This also was the perfect opportunity to share knowledge on how Plone and Volto works, how we can customize it to our needs, and encourage the growth of HIFIS. In an agile process, the forged collaboration then implemented the Form that was needed for the registration process, an AAI to allow easier logins, validation, and workflows that simplify the process for everyone.

uk: вхід без авторизації

name: How Plone helps to connect over forty thousand scientists


How to Patternslib with tiptap

uk: Комп'ютерні науки

description: tiptap is a headless editor which allows a fully customized UI and which has a strict tree based data model ensuring clean HTML code and allowing collaborative editing. We've built the Patternslib integration pat-tiptap at Syslab which is replacing our old HTML editor in Quaive. This talk shows how to use advanced Patternslib usage patterns to build the editor's UI including a custom toolbar and overlays and popups for image selection and link editing. The tiptap Plone 6 addon collective.tiptap also shows how to extend Plone with new JavaScript functionality without the need to recompile any bundle.

uk: вхід без авторизації


In-depth introduction to volto-slate

uk: Комп'ютерні науки

description: The development of volto-slate was started not only to improve the usability of Volto's text editor, but also to provide a solid foundation for smart, templated documents. We'll highlight the main user features of volto-slate and show you how to unlock its full potential, as a developer.

uk: вхід без авторизації


Institutional Assessment with Plone

uk: Комп'ютерні науки

description: Rafael will describe the creation of the York College Assessment Management System (YAMS) plug-in for Plone. Using agile development and Plone's built-in functionality such as workflow, versions, roles to create a system that serves the College in having standardized but flexible, has continuity as leadership changes, and serves as a repository for accreditation.

uk: вхід без авторизації


Introduction to React Hooks

uk: Комп'ютерні науки

description: In this talk we are going to learn about all the react hooks and how we can implement in our Volto project. We will also see a live transformation of a Volto component from class to hooks implementation.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: The tragic Rana Plaza building collapse in 2013 revealed to the world how little many global brands knew about where their products were being made. Following the disaster, demand for supply chain disclosure in the apparel sector was heightened. However, in response to these calls for greater transparency, supply chain disclosure has been inconsistent, inaccessible, of poor and varied quality, and stored in siloed databases. The Open Apparel Registry (OAR) was built to address all these data challenges. At its heart, the OAR exists to drive improvements in data quality for the benefit of all stakeholders in the apparel sector. Powered by a sophisticated name- and- address-matching algorithm, the tool creates one common, open registry of global facility names and addresses, with an industry standard facility ID. Join us to learn more about the challenges facing the apparel sector, including low levels of technical exposure and understanding of open data; collaborative work that’s being done to educate the sector on the power of open data, including the launch of the Open Data Standard for the Apparel Sector (ODSAS), and examples of how data from the Open Apparel Registry being freely shared and used is creating meaningful changes in the lives of some of global society’s most oppressed people.

uk: вхід без авторизації

name: Keynote: From Opaque to Open: Untangling Apparel Supply Chains with Open Data


Keynote: Plone 6 - Power and Control

uk: Комп'ютерні науки

description: Plone 6 is the first CMS on the market that combines the power features, best-in-class security, and scalability of an enterprise CMS with a state-of-the-art JavaScript frontend and an easy-to-use user interface that gives editors full control over the composition of pages.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: For our new intranet we had to create yet another set of views to display listings and pages and news items. This caused a full refactoring of all listing views used in the university's CMS, with some very nice features for our end users. For our Plone 5 migration we also migrated this functionality to mosaic tiles.

uk: вхід без авторизації

name: Playing with blocks and cards in Plone 5


uk: Комп'ютерні науки

description: This talk should make you more confident in modifying and extending Plone's powerful and efficient post-publish transformation tools. The first part covers plone.outputfilters - changing the behavior of TinyMCE images and the concepts of mime type transforms. The second part is on plone.transformchain - intercepting the entire HTML reply and changing the content before it is sent to the client.

uk: вхід без авторизації

name: Plone Outputfilters and TransformChain (how to display things differently)


Productizing Plone

uk: Комп'ютерні науки

description: Coming from a traditional web consultancy background, we've launched Quaive as a product-centric "built on Plone" solution. We still need our clients to be happy, and we still to a lot of consultancy. This talk highlights some of the tensions and pitfalls resulting from a hybrid consultancy-product business model. You'll walk away with insights on the importance of: design, expectation management, architecture, and balancing technical debt versus making a quick buck. This talk takes a product owner perspective and will be useful to both project managers working with clients, and to developers who want to deepen their understanding of the business side.

uk: вхід без авторизації


Pyruvate WSGI Server Status Update

uk: Комп'ютерні науки

description: At last year's Plone conference, I presented Pyruvate, a WSGI server implemented in Rust (and Python). Since then, Pyruvate has served as the production WSGI server in a couple of projects. In this talk I will give a project status update and show how to use Pyruvate with Zope/Plone and other Python web applications and frameworks. I will also present some use cases along with benchmark results and performance comparisons.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: For Plone 6 a lot of presentation layers needed some work: - Plone.com/org - Plone documentation - Plone training This is a short overview of what has changed, a demo of how you can now adjust the plone docs and training. And of course a warm invite to contribute.

uk: вхід без авторизації

name: Revamping the Plone training and documentation setup for Plone 6


uk: Комп'ютерні науки

description: Showcasing Volto's testing infrastructure and framework along with tips on how to achieve a strong QA among volto projects and addons by adhering to development workflow.

uk: вхід без авторизації

name: Plone Conference 2021 - Testing Volto Addons


The New Plone.org Built on Plone 6

uk: Комп'ютерні науки

description: I will discuss our plans to renew plone.org using Plone 6, the latest and greatest of all Plone-releases. This talk will contain a short history of plone.org, the rise and fall of plone.com, and give a glimpse to a new future with a renewed site. I will tell you about the challenges with the current site and the possibilities with the new one. It is also a call to action since we will need people participating in full or partial migration, design, theming, and content work. Practice what you preach and eat your own dogfood - plone.org should be the pinnacle of what you'll get with out-of-the-box Plone.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: We made a couple of talks for Plone Conference 2020. This talk is basically a summary of the story behind modernize Plone's classic UI + Theming based on this work. We're going to show how to create a theme for Plone 6 Classic UI based on Barceloneta and from scratch.

uk: вхід без авторизації

name: Plone Conference 2021 - Theming Plone 6 Classic UI


uk: Комп'ютерні науки

description: An introduction to the new Volto developer-targeted feature, the Pluggables framework.

uk: вхід без авторизації

name: Volto Pluggables: an argument for extensibility in CMS UI


Volto slots, portlets on steroids

uk: Комп'ютерні науки

description: We're taking a look at the current status of the Volto slots implementation, an analogue of the Plone portlets framework.

uk: вхід без авторизації


uk: Комп'ютерні науки

description: Distilled from the latest work done in Volto, we're showcasing some patterns, features, or enhancements that have landed in Volto from the last year to the present. We will also have a glimpse of what is ahead in the future of Volto with the new features roadmap.

uk: вхід без авторизації

name: What's new in Plone 6 frontend for developers


Why Relations are Awesome

uk: Комп'ютерні науки

description: In the last couple of month working with relations in Plone got a lot easier. In this talk I will present these improvements and show you can use relations to create a data-model that uses relations without shooting yourself in the foot.

uk: вхід без авторизації


COVID-19 Scatterplots: Waves as circles

keywords:
COVID-19
Big data
Germany
Scatterplots
Data Visualization
Incidence

uk: Комп'ютерні науки

description: Julia Haas is a data analyst and developer at mundialis. She holds an MSc in Geography. Her work usually focuses on the analysis of remotely sensed geospatial data and the processing of voluminous geodata. However, for the COVID-19 Scatterplots statistical data (COVID-19 incidence data) is being analysed. In this talk, Julia presented a newly developed application showing graphs for COVID-19 "status" in Germany. The graphs refer to incidence values and change of new cases in different regions of Germany.

uk: вхід без авторизації


uk: Математика, природничі науки

description: I will survey main results (both at the rigorous and the nonrigorous level) and open questions on the strongly correlated limit of DFT, including: - the connection between Hohenberg-Kohn-Lieb-Levy constrained-search and minimization of the interaction energy over |Ψ|2 (alias Kantorovich optimal transport) - the SCE (alias Monge) ansatz in the Kantorovich problem: where it works, where it fails - the new quasi-Monge ansatz [1] which - unlike the SCE ansatz - always yields the minimum Kantorovich cost, but whose data complexity scales linearly instead of exponentially with the number of particles/marginals - asymptotic and semi-empirical exchange-correlation functionals related to the strictly correlated limit - representability challenges. [1] G.Friesecke, D.Vögler, Breaking the curse of dimension in multi-marginal Kantorovich optimal transport on finite state spaces, SIAM J. Math. Analysis Vol. 50 No. 4, 3996-4019, 2018

uk: вхід без авторизації

name: The strong interaction limit of DFT: what's known, what's new, what's open (REVIEW)

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


uk: Математика, природничі науки

uk: вхід без авторизації

name: The strictly correlated electron functional in chemistry and physics (REVIEW)


uk: Математика, природничі науки

description: The strictly correlated electron approach to density functional theory, first proposed by Seidl and coworkers [1-4], offers a unique perspective on finite-temperature density functional theory and one of its application areas, simulations in the warm dense matter regime. In this region of phase space, many of the assumptions of traditional Kohn-Sham density functional theory no longer hold, requiring exchange-correlation free energy approximations that include explicit temperature dependence and better handling of complicated ionization processes. Formal analysis of the strong interaction limit for thermal ensembles will be demonstrated using the asymmetric Hubbard model, accompanied by discussions of the finite-temperature uniform gas and the competition between strong interaction and temperature in complicated physical systems. [1] M. Seidl, Phys. Rev. A 60, 4387 (1999). [2] M. Seidl, J. P. Perdew, and M. Levy, Phys. Rev. A 59, 51 (1999). [3] M. Seidl, P. Gori-Giorgi, and A. Savin, Phys. Rev. A 75, 042511 (2007). [4] P. Gori-Giorgi, G. Vignale, and M. Seidl, J. Chem. Theory Comput. 5, 743 (2009).

uk: вхід без авторизації

name: Temperature and the strong-interaction limit of density functional theory


uk: Математика, природничі науки

uk: вхід без авторизації

name: A mathematical introduction to Density Functional Theory and Kohn-Sham models (REVIEW)


uk: Математика, природничі науки

description: Time-dependent density functional theory relies on a one-to-one correspondence between external potentials in the N-particle Schrodinger equation and the one-particle densities they generate. Runge and Gross argued that this correspondence holds (up to a time-dependent constant in the potential) for sufficiently "nice" external potentials. I will discuss a mathematical setting for this argument and explain when it can be made fully rigorous. The interaction potentials play an important role for this and I will discuss the problems that arise in the presence of singular interactions, like the Coulomb potential. This is joint work with S. Fournais, M. Lewin, and T. Ostergaard Sorensen.

uk: вхід без авторизації

name: The role of interactions in the Runge-Gross Theorem


uk: Математика, природничі науки

description: The talk will focus on the leading term in the strong-interaction limit of the adiabatic connection that has as weak-interaction expansion the Møller-Plesset perturbation theory. Such term can be fully determined from a functional of the Hartree-Fock density. We analyse this functional and highlight similarities and differences with the strong-interaction limit of the density-fixed adiabatic connection case of Kohn-Sham density functional theory.

uk: вхід без авторизації

name: Strong-interaction limit of an adiabatic connection in Hartree-Fock theory


uk: Математика, природничі науки

description: We here discuss Hohenberg-Kohn-like theorems for systems with magnetic fields where different current densities are used together with the particle density. The situation is much more complicated than the case of no magnetic field, a fact that we further explore.

uk: вхід без авторизації

name: Hohenberg-Kohn-like theorems for current densities


uk: Математика, природничі науки

uk: вхід без авторизації

name: Essentials of 54 years of functional development in physical sciences (REVIEW)


uk: Математика, природничі науки

uk: вхід без авторизації

name: Memory in Time-Dependent Density Functional Theory: Exact Features and Approximations


uk: Математика, природничі науки

description: This theorem says that the true electron density of a molecule has a convergent Taylor expansion away from the positions of the nuclei. We discuss this, and an open problem about its structure at the nuclei.

uk: вхід без авторизації

name: The Holographic Density Theorem - and beyond


uk: Математика, природничі науки

description: In this talk, we discuss the phase diagram of the Hartree-Fock (HF) Homogeneous Electron Gas (HEG), both theoretically and numerically. We first recall the Overhauser spatial symmetry breaking which occurs for T=0 at all densities and we present a new lower bound on the energy gain due to this symmetry breaking. At high density we can prove that this gain can only be exponentially small. Then we focus on the fluid phase of the HF HEG and discuss spin symmetry breaking. We find two regions where the gas is either ferromagnetic or paramagnetic. We can partly justify the paramagnetic phase theoretically. This is joint work with Mathieu Lewin and Christian Hainzl.

uk: вхід без авторизації

name: Symmetry breaking in the Hartree-Fock jellium


uk: Математика, природничі науки

description: The Kohn-Sham SCE formulation is a natural way for using the strictly correlated electron (SCE) functional via an optimal transport formulation, especially when the Coulomb interaction dominates over the kinetic part. In this talk I will discuss some numerical issues associated with solving Kohn-Sham SCE using primal and dual formulations, as well as modeling issues for molecular systems regardless of how the optimal transport problem is solved. In the end I will discuss some on-going work for applying the Kohn-Sham SCE formulation to model problems with effective convex relaxation strategies. (Joint work with Yuehaw Khoo, Michael Lindsey and Lexing Ying.)

uk: вхід без авторизації

name: Kohn-Sham SCE formulation for molecules and lattice problems


uk: Математика, природничі науки

description: We extend the zero-temperature formalism of strictly correlated electrons in second quantization to the setting of finite temperature, naturally motivating the entropic regularization of a multi-marginal optimal transport problem on the binary hypercube. We introduce a semidefinite relaxation of this problem (mostly analogous to that of the zero-temperature setting) and briefly discuss its connection to the literature of probabilistic graphical models.

uk: вхід без авторизації

name: Strictly correlated electrons in second quantization at finite temperature


uk: Математика, природничі науки

description: We consider an infinite number of (interacting) quantum particles with constant spatial density filling the whole 2-dimensional space. We show that for small enough perturbations of this state at initial time, the system returns to this equilibrium for large times. The dynamics which we consider is of Hartree-type with localized interactions. This is a joint work with Mathieu Lewin.

uk: вхід без авторизації

name: Long time stability of constant density states for the Hartree model


uk: Математика, природничі науки

description: In this talk, we consider one relativistic nucleon interacting with classical σ and ω mesons fields in an atomic nucleus. I will explain that, in the nonrelativistic limit of nuclear physics, the model converges to a specific nonlinear Schrödinger-type equation with a mass depending on the solution itself. I will also discuss open problems concerning the case of several nucleons.

uk: вхід без авторизації

name: The relativistic semi-classical equation for a nucleon and its non-relativistic limit


uk: Математика, природничі науки

description: First I will introduce the strong and the relaxed formulations of the multi-marginal optimal transportation problem and I will compare them with the 2-marginal version. I will then explain which are the key tools which allowed the solution in the 2-marginal case and are missing in the multi-marginal problem. For particular costs advancement have been made and, for sufficiently general costs, partial solutions have been given. This positive results will be discussed in the second part of the expository talk. Finally some attention will be dedicated to costs which appeared in applications related to the theme of the meeting.

uk: вхід без авторизації

name: What is multi-marginal optimal transportation and why it is interesting - and difficult (REVIEW)


uk: Математика, природничі науки

uk: вхід без авторизації

name: Lieb-Oxford inequality and optimal transport


uk: Математика, природничі науки

description: I shall present the mathematical analysis of a limit problem in Density Functional Theory as a small parameter in front of the kinetic energy (the Planck constant) tends to zero, and explain how this relates to a bond dissociating model. This recent work shows that the multi-marginals optimal transport cost with Coulombian electron-electron repulsion may correctly describe the dissociation effect, and how the theme of fractional number of electrons appears naturally in this context, along with many open questions.

uk: вхід без авторизації

name: Bond dissociating limit for the energy of an aggregate of atoms

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


uk: Математика, природничі науки

description: After introducing the general setting of multimarginal optimal transport, we present some operators designed to approximate and regularize the tansport plans by keeping the marginals fixed. As an application to the Density Functional Theory, we show how to use this technique to study the properties of the mapping from the wave-functions to the single particle marginals.

uk: вхід без авторизації

name: Smoothing operators in multi-marginal optimal transport


uk: Математика, природничі науки

description: In this short communication, we will introduce the dual formulation of Multi-marginal Optimal Transport focusing on the case of repulsive costs functions (e.g. Coulomb). We will briefly discuss the connection with DFT and point out some recent results that appears in the literature in the last three years.

uk: вхід без авторизації

name: Kantorovich Duality for multi-marginal Optimal Transport


uk: Математика, природничі науки

description: In several applications where one studies interactions mediated by a long-range kernel, it is useful to decompose this kernel into finite-range contributions, and study them separately, without losing information on the system. In my talk I present a finite-range decomposition method developed in joint work with C. Cotar for the study of multimarginal transport with interaction kernels of the type 1/|x-y|^s. This helped apply to the study of Density Functional asymptotics, decomposition techniques that extend to much higher generality, and which seem to have high potential for algorithmic applications.

uk: вхід без авторизації

name: Finite range decomposition for multimarginal transport


uk: Математика, природничі науки

uk: вхід без авторизації

name: Numerical Methods for Kohn-Sham Density Functional Theory (REVIEW)


uk: Математика, природничі науки

uk: вхід без авторизації

name: Numerical Methods for Multi-Marginal optimal transport and Density Functional Theory (REVIEW)


uk: Математика, природничі науки

description: In this talk, we introduce methods from convex optimization to solve the multi-marginal transport type problems arise in the context of density functional theory. Convex relaxations are used to provide outer approximation to the set of N-representable 2-marginals and 3-marginals, which in turn provide lower bounds to the energy. We further propose rounding schemes to obtain upper bound to the energy.

uk: вхід без авторизації

name: Multimarginal optimal transport, density functional theory, and convex relaxation


uk: Математика, природничі науки

description: We consider two sharp next-order asymptotics problems, namely the asymptotics for the minimum energy for optimal point configurations and the asymptotics for the many-marginals Optimal Transport, in both cases with Coulomb and Riesz costs with inverse power-law long-range interactions. The first problem describes the ground state of a Coulomb or Riesz gas, while the second appears as a semi-classical limit of the Density Functional Theory energy modelling a quantum version of the same system. Recently the second-order term in these expansions was precisely described for inverse power-law interactions with power $\max(0,d-2)\le s (TCPL 201)

uk: вхід без авторизації

name: Equality of the Jellium and Uniform Electron Gas next-order asymptotic terms for Riesz potentials


uk: Математика, природничі науки

uk: вхід без авторизації

name: Metals vs insulators: screening and SCF convergence


uk: Математика, природничі науки

description: We introduce a relaxation of the OT problem (Moments Constrained Optimal Transport, MCOT) by minimizing the OT cost over the set of measures having only N moments against some given test functions equal to the ones of each marginal law. Using Tchakaloff’s theorem, we show that a finite discrete measure minimizes this problem which charges at most DN+2 points, with D the number of marginal laws. In addition, we prove the convergence of the MCOT problems towards the OT problem as the number of moments imposed goes to infinity, under some appropriate assumptions on the set of test functions. In this context, the convergence rate with respect to the number of moment constraints depends on the choice of test functions and cost considered. We present quantitative estimates for this rate in the particular cases of piecewise constant and affine test functions. Although the resulting MCOT problem is non convex, the linear dependency of the number of charged points of an optimum in the number of marginal laws and test functions is of algorithmic interest for the resolution of multi-marginal optimal transport problems with a very large number of marginal laws. This situation is typically encountered in the context of DFT. We thus propose two algorithms for the resolution of the MCOT problem which exploits this particular structure.

uk: вхід без авторизації

name: Approximation of OT problems with marginal moments constraints


uk: Математика, природничі науки

description: The two main challenges for Density Functional Theory (DFT) are strong correlation and the inclusion of London dispersion interactions. In this talk I will introduce our new formalism for dispersion interactions with fixed marginals (arXiv:1812.11840). The emphasis will be on the mathematical aspects, starting with the simple system consisting of two hydrogen atoms.

uk: вхід без авторизації

name: London dispersion interactions with fixed marginals