Research Seminar RTG 2131
Archive of Talks from Previous Semesters
Summerterm 2021
At Ruhr University Bochum (Online)
Winterterm 2020/21
At TU Dortmund (Online).
Date | Speaker | Title |
---|---|---|
02.11. | Holger Rauhut | Structured Random Matrices in Compressive Sensing and Suprema of Chaos Processes |
09.11. | Nina Gantert | Large deviations for lacunary sums |
16.11. | Vadim Gorin | Infinite beta random matrix theory |
23.11. | Felix Pogorzelski | Mathematical quasicrystals and unique ergodicity |
30.11. | Laszlo Erdös | Edge Universality for Non-Hermitian Random Matrices |
07.12. | Patrik Ferrari | KPZ universality in mathematics and physics |
14.12. | Erika Hausenblas | Numerical Modelling of a stochastic Gray-Scott system |
04.01. | Matthias Schulte | Non-standard limits for a family of autoregressive stochastic sequences |
11.01. | Amin Coja-Oghlan | Disordered systems and random graphs |
18.01. | Michael Voit | Limit theorems for Bessel processes of large dimensions and free convolutions |
25.01. | Hugo Duminil-Copin | Emerging symmetries in 2D percolation |
01.02. | Larry Goldstein | Relaxing Gaussian Assumptions in High Dimensional Statistical Procedures |
08.02. | Uta Freiberg | Analysis on the Stretched Sierpinski Gasket |
Summerterm 2020
Apr 27 |
Thomas Kruse, University of Giessen We present new approximation methods for high-dimensional PDEs and BSDEs. A key idea of our methods is to combine multilevel approximations with Picard fixed-point approximations. We prove in the case of semilinear heat equations with Lipschitz continuous nonlinearities that the computational effort of one of the proposed methods grows polynomially both in the dimension and in the reciprocal of the required accuracy. We illustrate the efficiency of the approximation methods by means of numerical simulations. The talk is based on joint works with Weinan E, Martin Hutzenthaler, Arnulf Jentzen, Tuan Nguyen and Philippe Von Wurstemberger. |
May 4 |
Cécile Mailler, University of Bath In this joint work with Nikolaos Fountoulakis, Tejas Iyer and Henning Sulzbach (Birmingham), we study a random graph model introduced by Bianconi and Rahmede in 2015. This model is a simplicial complex model that generalises Apollonian networks and the random recursive trees, by, in particular, adding random weights to the nodes. For this general model, we prove limiting theorems for the degree distribution, and confirm the conjecture of Bianconi and Rahmede on the scale-free propoerties of this random graph. |
May 11 |
Andreas Basse-O’Conner, Aarhus University Infinite divisible laws play a crucial role in many areas of probability theory. This class of laws corresponds exactly to all the possible weak limits of triangular arrays of random variables, due to the generalized central limit theorem, and hence infinite divisible laws are natural generalizations of the Gaussian laws. In this talk we will discuss properties and representations of infinite divisible probability measures on Banach spaces, with particular focus on their Lévy-Khintchine representations and their shot noise representations. We will see that these representations depend heavily on the Banach space under consideration. In particular, both the geometry of the Banach space and its “size” will play a big role. Many examples of high dimensional probability measures come from stochastic process theory, and we will illustrate the results within this framework. |
May 18 |
Manuel Cabezas, Pontificia Universidad Católica de Chile Activated random walks is a system of particles which perform random walks and can spontaneously fall asleep, staying put. When an active particle falls on a sleeping one, the sleeping particle becomes active and continues moving. The system displays a phase transition in terms of the density of particles. If the density is small, all particles will eventually sleep forever, while, if the density is high, the system can sustain a positive proportion of active particles. In this talk we describe the critical behavior of the model in the totally asymmetric case. Joint work with Leo Rolla. |
May 25 | Airam Blancas Benítez, Stanford University
Coalescent models for trees within trees Phylogenetic gene trees are contained within the branches of the species trees. In order to model genealogy backwards in time, of both, gene trees and species trees, simple exchangeable coalescent (snec) process are defined and characterized in talk. In particular, we study the coming down form infinity property for the so called nested Kingman. Finally, we present a model to include population structure in gene lineages. |
June 8 | Geronimo Uribe Bravo, UNAM
On the profile of trees with a given degree sequence For a given (plane) tree $\tau$, let $N_i$ be the quantity of individuals with $i$ descendants and define its degree sequence as $s=(N_i)_{i\geq 1}$. We will be interested in the uniform distribution on trees whose degree sequence is $s$. We give conditions for the convergence of the profile (aka the sequence of generation sizes) as the size of the tree goes to infinity. This gives a more general formulation and a probabilistic proof of a conjecture due to Aldous for conditioned Galton-Watson trees. Our formulation contains results in this direction obtained previously by Drmota-Gittenberger and Kersting. The technique, based on path transformations for exchangeable increment processes, also gives us a (partial) compactness criterion for the inhomogeneous continuum random tree. |
June 15 |
Olivier Hénard, Université Paris-Sud Lackner and Panholzer (2015) introduced the parking process on trees as a generalization of the classical parking process on the line. |
June 22 |
Adrian Gonzalez Casanova, UNAM The relation between these two important families of processes has been investigated in some cases. In particular, in a a renowned paper by seven authors, the $\beta$-coalescents are obtained as a functional of two independent $\alpha$-stable branching processes. |
June 29 |
Antoine Lejay, Institut Élie Cartan de Lorraine (IECL)
We discuss the problem of the Monte Carlo simulation of sample paths. The Embeddable Markov Chain Schemes simulate the exact positions of a diffusion at some hitting times which are not known but only approximated. Such schemes aim at overcoming the situations in which the Euler-Maruyama scheme cannot be used, because of the presence of discontinuous coefficients, interfaces, sticky points, … |
July 6 |
Thomas Godland, University of Münster In this talk, I consider generate a conical tessellation of the Euclidean |
July 13 |
Osvaldo Angtuncio, UNAM In this talk, we introduce the model of uniform multitype forests with a given degree sequence (MFGDS). The construction is done using the results of Chaumont and Liu 2016, and a novel path transformation on multidimensional discrete exchangeable increment processes, which is a generalization of the Vervaat transform. By mixing the laws of MFGDS, one obtains multitype Galton-Watson (MGW) forests conditioned with the number of individuals of each type (CMGW). We also obtain the joint law of the number of individuals by types in a MGW forest, generalizing the Otter-Dwass formula. This allows us to get enumerations of multitype forests with a combinatorial structure (plane, labeled and binary forest), having a prescribed number of roots and individuals by types. Finally, under certain hypotheses, we give an easy algorithm to simulate CMGW forests, generalizing the unitype case given by Devroye in 2012. The previous results can be considered as the first step to obtain the profile of the multitype Lévy forest. |
Winterterm 2019/20
at Ruhr University Bochum
Oct 14 | Pascal Maillard, Toulouse (France) 1-stable fluctuations of branching Brownian motion at critical temperature |
Oct 21 | Holger Sambale, Bielefeld Higher order concentration of measure |
Oct 28 | Carina Betken, Bochum Poisson cylinder processes: concentration inequalities and a CLT for the volume |
Nov 4 | Erik Broman, Uppsala (Sweden) The Poisson cylinder process in Euclidean and Hyperbolic space |
Nov 11 | Nina Holden, ETH Zürich (Switzerland) Cardy embedding of random planar maps |
Nov 18 | Leif Döring, Mannheim Existence, Uniqueness and Explosion results for stable SDEs |
Dec 2 | Hanna Döring, Osnabrück Crossing Numbers and Stress of Random Geometric Graphs |
Dec 9 | Joseph Najnudel, Bristol (UK) On smooth mesoscopic linear statistics of the eigenvalues of random permutation matrices |
Jan 6 | Karen Habermann, Sorbonne Université Paris (France) A semicircle law and decorrelation phenomena for iterated Kolmogorov loops |
Jan 13 | Steffen Dereich, Münster A central limit theorem for averaged gradient descend in deep learning applications |
Jan 20 | Quan Shi, Mannheim Measure-valued diffusions with Poisson-Dirichlet stationary distributions |
Jan 27 | George Andriopoulos, Shanghai (China) Scaling limits of random walks in random environments on trees and related parameters |
Summerterm 2019
at Ruhr University Bochum
Apr 8 |
Kristina Schubert, Dortmund, RTG |
Apr 15 |
Anna Gusakova, Bochum, RTG |
May 6 |
Jere Koskela, Warwick |
May 13 |
Yuriy Nemish, Klosterneuburg, IST |
May 20 |
Michael Soerensen, Kopenhagen |
May 27 |
Anna Paola Todino, Bochum |
Jun 17 |
Max Fathi, Toulouse |
Jun 24 |
Miklós Kornyik, Budapest |
Jul 1 |
Markus Reiss, Berlin |
Jul 8 | David Damanik, Houston The Fürstenberg-Ishii Criterion for a Positive Lyapunov Exponent and Applications to Anderson Localization |
Winterterm 2018/19
at University Duisburg-Essen
Oct 8 |
Abel Klein, Irvine (USA) |
Oct 8 | Tobias Müller, Groningen (Netherlands) The critical probability for confetti percolation equals 1/2 |
Oct 15 |
Vitalii Konarovskyi, Leipzig |
Oct 22 | PI-meeting |
Oct 29 |
Piotr Graczyk, Angers (France) |
Nov 5 |
Vlada Limic, Strasbourg (France) |
Nov 12 |
Wioletta Ruszel, Delft (Netherlands) |
Nov 19 |
Noemi Kurt, Berlin |
Nov 26 |
Tran Viet Chi, Lille (France) |
Dec 3 |
Martin Slowik, Berlin |
Dec 17 |
Michael Hinz, Bielefeld |
Jan 7 |
Sebastian Riedel, Berlin |
Jan 14 |
Mike Keane, Leiden (Netherlands) |
Jan 21 |
Thomas Mikosch, Copenhagen (Denmark) and Bochum |
Jan 28 |
Johannes Heiny, Bochum (RTG) |
Summerterm 2018
at Ruhr University Bochum
Apr 16 |
Martin Venker, Bochum
Universality in Non-Hermitian Random Matrix Theory: Fixed Trace Ensembles
|
Apr 19 |
Ciprian Tudor, Lille (France)
Variation of the solution to the wave equation
|
Apr 23 |
Thomas Kriecherbauer, Bayreuth
Floquet Theory for Markov processes and a nonlinear generalisation
|
Apr 30 |
Christian Döbler, Luxemburg
Normal approximation of U-statistics via contractions
|
May 7 |
Ilya Molchanov, Bern (Switzerland)
The semigroup of metric measure spaces and its infinitely divisible measure
|
May 14 |
Beatrice-Helen Vritsiou, Ann Arbor (Michigan, USA)
Selberg-type integrals and the variance conjecture for the Schatten classes
|
May 28 |
Maite Wilke-Berenguer, Berlin
The Wright-Fisher model with selection in a random environment
|
Jun 4 |
Eliza O’Reilly, Austin (Texas, USA)
Reach of Repulsion for Determinantal Point Processes in High Dimensions
|
Jun 18 |
Yacine Barhoumi-Andréani, Zurich (Switzerland)
On the mid-coefficient of a random unitary matrix
|
Jun 25 |
Paolo Pigato, Berlin
Estimation of piecewise-constant coefficients in a stochastic differential equation
|
Jul 2 |
Priscilla Greenwood, Vancouver (Canada)
Quasi-patterns of synchronization produced by a Mexican hat coupling of quasi-cycles
|
Jul 9 |
Daniel Hug, Karlsruhe
Geometric Stability, mass transportation and stochastic geometry
|
Jul 16 |
Piotr Graczyk, Angers (France)
Squared Bessel particle systems and Wishart processes
|
Winterterm 2017/18
at Ruhr University Bochum
Oct 16 |
Peter Mörters, Köln
Metastability of the contact process on evolving scale-free networks |
Oct 23 |
Ivan Veselic, Dortmund
Glivenko Cantelli and Ergodic Theorem on groups
|
Nov 6 |
Anita Winter, Duisburg-Essen
Brownian motion on graph-like metric spaces and the cover time bound
|
Nov 13 |
Sergio Andraus, Tokyo
Dunkl processes and particle systems: dynamics due to the exchange interaction
|
Nov 20 |
Masha Gordina, Connecticut
Stochastic Analysis and Geometric Functional Inequalities
Chiranjib Mukherjee, Münster
Recent developments in compact large deviation theory and applications to statistical mechanics
|
Nov 27 |
Frank Aurzada, Darmstadt
Persistence probabilities for fractional processes
|
Dec 4 |
Philippe Bougerol, Paris
The Pitman theorem and random walks on trees and hyperbolic spaces
|
Dec 11 |
Mira Shamis, London
The Curie-Weiss model at complex temperature
|
Dec 18 | RTG Feedback meeting |
Jan 8 |
Günter Last, Karlsruhe
How to find an extra excursion in Brownian motion
|
Jan 11 |
Alexander Lindner, Ulm
Quasi-infinitely divisible distributions
|
Jan 15 |
Simone Warzel, München
Localization-delocalization transitions in effective random matrix models
|
Jan 22 |
Apostolos Giannopoulos, Athens
On the MM*-estimate for isotropic convex bodies: upper bounds for the mean norm and the mean width
|
Jan 29-30 | Workshop Statistical Mechanics |
Summerterm 2017
at TU Dortmund
April 24th | Sandra Kliem, University of Duisburg-Essen Travelling wave solutions to the KPP equation with branching noise |
May, 8th | Karl-Theodor Sturm, University of Bonn Heat flow, optimal transport, and Ricci curvature on metric measure spaces |
May, 15 th |
Wolfgang König, TU Berlin |
May, 22nd | Elena Pulvirenti University of Bonn
Metastability for the Widom-Rowlinson model |
May, 29th |
Joscha Prochno, University of Hull, UK |
June, 8th |
René Schilling, University Dresden |
June, 12th | Jean-Yves Welschinger, University of Lyon Expected topology of a random subcomplex in a simplicial complex |
June, 19th |
Anne Estrade, University of Paris
A test of Gaussianity based on the Euler characteristic of excursion sets |
June, 26th |
Christian Bender, University Saarbrücken |
July, 3rd |
Paul Doukhan, University Cergy-Pontoise |
July, 10th |
Lisa Hartung, New York University |
July, 17th | Larry Goldstein, UCLA
Non asymptotic distributional bounds for the Dickman approximation of the running time of the Quickselect algorithm
|
Wintertherm 2016/17
at Ruhr University Bochum
October 24th | Sebastian Andres, University of Cambridge, UK Diffusion processes on Branching Brownian Motion |
November 7th | David Croydon, University of Warwick, UK Scaling limits of stochastic processes accociated with resistance forms |
November 14th |
Ngoc Mai Tran, University of Bonn |
November 21st | Christoph Külske, University of Bochum
Gibbs-non Gibbs transitions for point particles under time-evolution: the Widom-Rowlinson model under spin flip |
November 28th | Jan Nagel, TU München Large deviations for random matrices and sum rules |
December 5th | Julian Grothe, University of Bochum Gaussian polytopes and simplices - a cumulant based approach |
December 12th | Uta Freiberg, University of Stuttgart
Spectral asymptotics on random Sierpinski gaskets |
December 19th | RTG-Feedback meeting |
January 9th |
Matthias Schulte, University of Bern
Malliavin-Stein method, stochastic geometry and beyond |
January 16th | Sandra Palau Calderon, University of Bath Generalisations of continuous-state branching processes |
January 23rd | Sara Mazzonetto, University of Potsdam, Lille Exact simulation of Brownian diffusions with drift admitting jumps |
January 30th | Elisabeth Werner, Case Western Reserve University Cleveland Approximation of convex bodies by polytopes |
Summertherm 2016
at University Duisburg-Essen
April 18th | Jeannette Woerner, University of Dortmund An introduction to fractional processes and related limit theorems |
April 25th |
Martin Hutzenthlaler, University of Duisburg-Essen |
May 2nd |
Pierre Calka, University of Rouen |
May 9th | Angelika Rohde, University of Bochum Spectral analysis of high-dimensional sample covariance matrices with missing observations |
May 23rd | Maurizia Rossi, University of Luxemburg Non-universality of nodal length distribution for arithmetic random waves |
May 30th | Margherita Disertori, University of Bonn History dependent stochastic processes and non linear sigma models |
June 6th | Imre Barany, Hungarian Academy of sciences Budapest On the randomized integer convex hull |
June 13th | Markus Heydenreich, LMU München Scale-free percolation |
June 20th |
Ehsan Azmoodeh, University of Helsinki
An attempt to small deviations |
June 27th | Holger Kösters, Bielefeld Products of Independent Random Matrices: From Singular Values to Eigenvalues |
July 4th | Alexander Drewitz, University of Köln The maximal particle of branching random walk in spatially random branching environment |
July 11th | Sebastian Scholtes, University of Aachen Old and new on sets of positive reach |
July 18th | Hui He, University of Beijing From Galton-Watson trees to Levy trees: Scaling limits, pruning process and reduced trees |
Wintertherm 2015/16
at Ruhr University Bochum
October 26 |
Sander Dommers (University of Bochum) |
November 2 |
Bram Petri (University of Bonn) |
November 9 |
Claudio Dursatanti (University of Bochum) |
November 16 |
Nicola Kistler (University of Frankfurt) |
November 23 |
Tobias Fissler (University of Bern) |
November 30 |
Richard Kraaij (University of Delft) |
December 7 |
Matthias Löwe (University of Münster) |
December 14 |
Sabine Jansen (University of Bochum) |
December 21 |
Mark Podolskij (University of Aarhus) |
January 11 |
Fabian Gerle (University of Duisburg-Essen) |
January 18 |
Vaidotas Characiejus (University of Bochum) |
January 25 |
Raghid Zeineddine (University of Dortmund) |
January 1st |
Vaidotas Characiejus(university of Bochum) |
February 8 |
Arnulf Jentzen (ETH Zürich) |