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Monday, 27.05.2024, 14:00 (WIAS-ESH)
Joint Research Seminar on Nonsmooth Variational Problems and Operator Equations / Mathematical Optimization
Qi Wang, WIAS:
Robust multilevel training of artificial neural networks
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
In this talk, we will introduce a multilevel optimizier for training of an artificial neural network. We are particularly interested in nerual networks to learn the hidden physical law or nonlinear mapping from the given data using algebraic multigrid strategies. And we would like to give some further insight into the potential of multilevel optimization methods in the end.

Further Informations
Joint Research Seminar on Nonsmooth Variational Problems and Operator Equations

Host
WIAS Berlin
Wednesday, 29.05.2024, 10:00 (WIAS-ESH)
Forschungsseminar Mathematische Statistik
Prof. Dr. Tailen Hsing, University of Michigan, USA:
A functional-data perspective in spatial data analysis
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
More and more spatiotemporal data nowadays can be viewed as functional data. The first part of the talk focuses on the Argo data, which is a modern oceanography dataset that provides unprecedented global coverage of temperature and salinity measurements in the upper 2,000 meters of depth of the ocean. I will discuss a functional kriging approach to predict temperature and salinity as a smooth function of depth, as well as a co-kriging approach of predicting oxygen concentration based on temperature and salinity data. In the second part of the talk, I will give an overview on some related topics, including spectral density estimation and variable selection for functional dat

Further Informations
Der Vortrag findet auch via Zoom statt: https://hu-berlin.zoom-x.de/j/69268586742?pwd=bDZJQTk5TGdnUkVCUk9RWGdsWC9vdz09 Meeting-ID: 692 6858 6742, Passwort: 021844

Host
Humboldt-Universität zu Berlin
Universität Potsdam
WIAS Berlin
Wednesday, 29.05.2024, 16:15 (WIAS-ESH)
Berliner Kolloquium Wahrscheinlichkeitstheorie
Nikolay Barashkov, MPI Leipzig:
Φ43 as a Markov Field
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
Random Fields with posses the Markov Property have played an important role in the development of Constructive Field Theory. They are related to their relativistic counterparts through Nelson Reconstruction. In this talk I will describe an attempt to understand the Markov Property of the Φ 4 measure in 3 dimensions. This is based on Joint work with T. Gunaratnam.

Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
Wednesday, 29.05.2024, 17:15 (WIAS-ESH)
Berliner Kolloquium Wahrscheinlichkeitstheorie
Shige Peng, Shandong University:
Space-time white noises in a nonlinear expectation space
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
Under the framework of nonlinear expectation, we introduce a new type of random fields, which contains a type of space-time white noise as a special case. Based on this result, we also introduce a space white noise. Different from the case of linear expectation, in which the probability measure is given and fixed. Under the uncertainty of probability measures, space white noises are intrinsi- cally different from the space cases, which is generalized from G-Gaussian processes which are different from a G-Brownian motion (joint work with Xiaojun JI).

Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
Tuesday, 04.06.2024, 10:15 (WIAS-406)
Seminar Nichtlineare Optimierung und Inverse Probleme
Dr. Łukasz Płociniczak, Wrocław University of Science and Technology, Polen:
From hydrology, through climatology to hemo- and lymphodynamics: Mathematical modelling approaches
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Weierstraß-Hörsaal (Raum: 406)

Host
WIAS Berlin
Tuesday, 04.06.2024, 14:30 (WIAS-ESH)
Seminar Numerische Mathematik
Daniel Runge:
Mass-conservative reduced basis approach for heterogeneous catalysis
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
WIAS Berlin
Wednesday, 05.06.2024, 11:30 (WIAS-405-406)
Seminar Interacting Random Systems
Gerónimo Uribe Bravo, Universidad Nacional Autónoma de México, Mexiko:
A pathwise approach to time-change
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Raum: 405/406

Abstract
Time-change equations are a generalization of ordinary differential equations which are driven by the random, irregular, and possibly densely discontinuous sample paths of the typical stochastic process. They can be thought of as a multiparameter version of the method of time-change and can be given a pathwise theory. Time-change equations can lead to deep results on weak existence and uniqueness of stochastic differential equations and posses a robust strong approximation theory. However, time-change equations are not restricted to Markovian or semimartingale settings. In this talk, we will go through some examples of time-change equations which can be successfully analyzed. These include (multidimensional) branching and affine processes, scaling limits of profiles of random trees, sticky Lévy processes or Doeblin´s mostly unknown proposal for diffusion processes. We shall also comment on some open problems they suggest.

Further Informations
Seminar Interacting Random Systems (Hybrid Event)

Host
WIAS Berlin
Wednesday, 12.06.2024, 16:15 (WIAS-ESH)
Berliner Kolloquium Wahrscheinlichkeitstheorie
Eduardo Abi Jaber, Ecole Polytechnique:
tba
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
Wednesday, 26.06.2024, 09:00 (TUB HE101)
MATh.en.JEANS
Schüler:innen-Konferenz: MATh.en.JEANS
more ... Location
Technische Universität, Straße des 17. Juni 136, 10623 Berlin, HE101

Abstract
https://wias-berlin.de/people/kern/mejkonferenz24/researchers.jsp

Host
WIAS Berlin
Wednesday, 26.06.2024, 16:15 (WIAS-ESH)
Berliner Kolloquium Wahrscheinlichkeitstheorie
Benjamin Jourdain, École des Ponts ParisTech:
tba
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
Wednesday, 26.06.2024, 17:15 (WIAS-ESH)
Berliner Kolloquium Wahrscheinlichkeitstheorie
Noemi Kurt, Goethe University Frankfurt:
tba
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
July 1, 2024 (WIAS-ESH)
Workshop/Konferenz: Developments in Computational Finance - Honoring John Schoenmakers on the occasion of his retirement
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
WIAS Berlin
Wednesday, 03.07.2024, 14:14 (WIAS-ESH)
Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Dr. Andreas Vikelis, Universität Wien, Österreich:
Measure-valued solutions for non-associative finite plasticity
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
The variational treatment of evolutionary nonassociative elasto-plasticity at finite strains remains unexplored. In this direction, following the concept of energetic solutions, we present an existence result for measure-valued solutions of the quasistatic evolution problem which are stable and balance the energy. In particular, we apply a modification of the standard timediscretization scheme, considering Young measures generated by piecewise constant interpolants of time-discrete solutions of a properly defined minimization problem. A key point in our analysis is the limit passage in the dissipation. The later calls for time-continuity properties of the stresses which are not expected in the quasistatic framework. To overcome this obstacle we introduce a regularization of the generalized stress in the definitionof our energetic solutions. Joint work with Ulisse Stefanelli.

Further Informations
Oberseminar “Nichtlineare Partielle Differentialgleichungen” (Langenbach Seminar)

Host
Humboldt-Universität zu Berlin
WIAS Berlin
Wednesday, 10.07.2024, 14:15 (WIAS-ESH)
Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Prof. Dr. Caroline Lasser, Technische Universität München:
Variational Gaussian approximation for quantum dynamics
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
The talk considers the time-dependent Schrödinger equation with smooth magnetic and electric potentials in semiclassical scaling. We analyse nonlinearly parametrized approximations by single Gaussian wave packets via the Dirac--Frenkel variational principle. We derive ordinary differential equations of motion for the parameters of the variational solution. We present L2-error bounds and unexpectedly accurate observable error bounds. This is joint work with S. Burkhard, B. Dörich, and M. Hochbruck.

Host
Humboldt-Universität zu Berlin
WIAS Berlin
Wednesday, 10.07.2024, 16:15 (WIAS-ESH)
Berliner Kolloquium Wahrscheinlichkeitstheorie
Dan Crisan, Imperial College London:
tba
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
Wednesday, 10.07.2024, 17:15 (WIAS-ESH)
Berliner Kolloquium Wahrscheinlichkeitstheorie
Jiniao Qiu, U of Calgary:
tba
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Host
Humboldt-Universität zu Berlin
Technische Universität Berlin
WIAS Berlin
Monday, 15.07.2024, 10:00 (WIAS-ESH)
MATH+ Thematic Einstein Semester on “Mathematics for Quantum Technologies”
Prof. Ulf Leonhardt, Weizmann Institute of Science, Israel:
First advanced lecture of the series “Forces of the quantum vacuum” .
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
Topic: Setting the scene
Quantization of the electromagnetic field in media and in space-time
Normal modes and harmomic oscillators
Zero-point energy
Casimir's cavity: 1D case, zeta-function renormalization
Casimir's cavity: 3D case, Casimir's renormalization

Host
WIAS Berlin
Einstein Foundation Berlin
Tuesday, 16.07.2024, 10:00 (WIAS-ESH)
MATH+ Thematic Einstein Semester on “Mathematics for Quantum Technologies”
Prof. Ulf Leonhardt, Weizmann Institute of Science, Israel:
Second advanced lecture of the series “Forces of the quantum vacuum” .
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
Topic: Lifshitz theory
The need for a theory in dispersive and dissipative media
Point-splitting method
Fluctuation-dissipation theorem
Kubo-Martin-Schwinger relation
Lifshitz formula in planar, piece-wise homogenous media

Host
WIAS Berlin
Einstein Foundation Berlin
Thursday, 18.07.2024, 10:00 (WIAS-ESH)
MATH+ Thematic Einstein Semester on “Mathematics for Quantum Technologies”
Prof. Ulf Leonhardt, Weizmann Institute of Science, Israel:
Third advanced lecture of the series “Forces of the quantum vacuum” .
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
Topic: Applications
Imaginary frequencies for capturing the broad band of quantum forces
Thermal Casimir effect
Perfectly conducting cavity
Magnetic mirror and Casimir repulsion
Permittivity hierarchy and repulsive Casimir forces
Negative refraction and quantum levitation
Engineering in the imaginary part of the spectrum


Host
WIAS Berlin
Einstein Foundation Berlin
Friday, 19.07.2024, 10:00 (WIAS-ESH)
MATH+ Thematic Einstein Semester on “Mathematics for Quantum Technologies”
Prof. Ulf Leonhardt, Weizmann Institute of Science, Israel:
Fourth advanced lecture of the series “Forces of the quantum vacuum” .
more ... Location
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstract
Topic: Outlook
The quantum vacuum seen by accelerated observers (relativistic acceleration, Rindler coordinates, Unruh effect)
Entanglement in the quantum vacuum
Classical analogue of the Unruh effect
The case for a Casimir cosmology

Host
WIAS Berlin
Einstein Foundation Berlin