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Austrian Stochastics Days 2024

 

  • Research Seminar & Colloquium

Inn'formal Probability Seminar

 

  • Past Events:

    Conferences


    TITLE Branching in Innsbruck
    SPEAKER(S) check website
    TIME 23 September -  26 September 2019
    LOCATION TBA
    ABSTRACT The goal of this conference is to bring together young and senior researchers working in the field of branching processes, with a special focus on branching random walks and branching Brownian motion. We aim to create a stimulating atmosphere for the exchange of ideas and to foster new collaborations. There will be plenty of time for discussions.


    TITLE Spring School
    SPEAKER(S) check website
    TIME 25 February - 1 March 2019
    LOCATION building S2 07, Hochschulstraße 6, 64289 Darmstadt
    ABSTRACT Stochastic geometry is a classical topic in probability theory and has seen interesting developments in past years. The aim of this school is to introduce PhD students and young post-docs to some aspects of this development. The core of the school are two mini courses, each consisting of five 90-minute lectures:

    Zakhar Kabluchko (Münster) (Abstract)
    Joseph Yukich (Lehigh) (Abstract+Lecture notes).


    TITLE Spring School: Complex Networks
    SPEAKER(S) check website
    TIME 2 March -  6 March 2020
    LOCATION TU Darmstadt - building S2 04
    ABSTRACT The mathematical study of Complex Networks is an active subject in probability with many real world applications. The aim of this school is to introduce PhD students and young post-docs to some recent developments in this field. The core of the school consists of two mini courses, each consisting of five 90-minute lectures by

    Remco van der Hofstad (Eindhoven)
    Frank den Hollander (Leiden).



    Research Seminar & Colloquium


    TITLE Zufällige räumliche Permutationen und Schlaufen
    SPEAKER(S) Prof. Dr. Volker Betz, Technische Universität Darmstadt
    TIME 23 January 2020, 4:15 pm
    LOCATION Campus Technik (Innsbruck), Technikerstrasse 13b, HSB 4 (EG)
    ABSTRACT Die Modelle zufälliger räumlicher Permutationen und Schlaufen lassen sich gut anschaulich erklären, und enthalten leicht zu formulierende, aber sehr schwierig zu lösende Probleme.

    Als einfachstes Beispiel sei U eine (große) endliche Teilmenge des Gitters Z^d. Zwischen den Punkten von U fügt man nun Kanten so ein, dass jeder Punkt entweder isoliert (keine Kante) ist, oder genau zwei Kanten an ihn angrenzen. Weiter darf man Kanten nur zwischen Punkten einfügen, die im Gitter U benachbart sind. Offenbar ergibt sich hierdurch eine Sammlung von isolierten Punkten und geschlossenen “Schlaufen”. Unter allen (endlich vielen) Möglichkeiten, eine durch obige Regel erlaubte Konfiguration von Kanten zu erzeugen, wählt man nun zufällig eine aus, allerdings nicht gleichverteilt, sondern mit einer Zähldichte, die proportional zu $\exp(- \alpha K)$ ist, wobei K die Anzahl der eingezogenen Kanten ist. Eine (ungelöste) Frage ist beispielsweise, wie sich (im Grenzwert unendlich großer Gebiete U) die erwartete Länge der Schlaufe verhält, die den Punkt $0 \in \bbZ^d$ enthält.

    In meinem Vortrag werde ich verschiedene Varianten dieser Modelle vorstellen und auf einige ihrer vermuteten und bewiesenen Eigenschaften eingehen. Ebenso werde ich kurz über die auf den ersten Blick überraschenden Beziehungen zur Theorie der Bose-Einstein-Kondensation sprechen. Der Vortrag richtet sich an ein allgemeines mathematisches Publikum und kann ohne weitreichende Kenntnisse der Wahrscheinlichkeitstheorie gut verstanden werden.

    The talk will be given in English if there is demand.


    TITLE Transport beyond Brownian Motion - Colored noise
    SPEAKER(S) Thomas Franosch, Institut für Theoretische Physik UIBK
    TIME 14 November 2019, 4:15 pm
    LOCATION Institut für Mathematik UIBK, Technikerstraße 13, 7. OG - Seminarraum 734
    ABSTRACT Brownian motion is one of the pillars of statistical physics with applications ranging from astrophysics to biological physics. The theoretical foundation is well understood since Einstein and Smoluchowski introduced a probabilistic interpretation to derive diffusion as a macroscopic law. In modern language, the diffusion propagator follows from the central limit theorem. In stochastics the paradigm of Brownian motion sets the foundation for virtually all stochastic processes in continuous time.

    Interestingly, in the experimental realization of a suspended mesosized particle in a simple fluid, which triggered the theoretical development, the underlying dynamics does not fulfill completely the assumptions of Brownian motion. This is trivially obvious at the shortest time scales, where the molecular nature of the surrounding fluid becomes relevant. However, quite surprisingly, even at long times, the dynamics displays hidden long-range correlations which only algebraically fade out.

    In the presentation I will provide 'physicist's view' on Brownian motion including some historic remarks on the key ideas of the modern theoretical description. Recent experimental progress [1,2] has allowed to direclty monitor the subleading correlations in the mean-square displacement which have been anticipated long time ago by hydrodynamic arguments.

    [1] T. Franosch et al., Nature 478, 85-88 (2011)

    [2] S. Jeney et al., Phys. Rev. Lett. 100, 240604 (2008)


    TITLE How Complex is a Random Picture
    SPEAKER Frank Aurzada (TU Darmstadt)
    TIME Thursday, 13 June 2019, 5:00 pm
    LOCATION Campus Technik, HSB4
    ABSTRACT We study the amount of information that is contained in "random pictures“, by which we mean the sample sets of a Boolean model. The talk will explain the concept of a Boolean model, which includes a model for a "completely random distribution of points in the plane". Then we shall study different concepts making the term "amount of information“ mathematically precise.

    The presented results are based on a joint work with Mikhail Lifshits (St. Petersburg).


    TITLE Branching random walks and the Fisher-KPP equation
    SPEAKER Alexander Drewitz
    TIME 24 January 2019, 5:00 pm
    LOCATION Universität zu Köln, Vortrag im Kolloquium
    ABSTRACT Branching random walks and branching Brownian motion are stochastic processes which have been receiving a lot of attention during the last couple of decades. They appear in a variety of more applied sciences (such as biology, statistical mechanics, and computer science) and exhibit deep connections to partial differential equations.

    We will provide a survey of some classical results and discuss the interesting effects of extensions to spatially heterogeneous branching rates.


    TITLE Large deviations and distances in the spatial preferential attachment model
    SPEAKER Dr. Christian Mönch (Universität Mannheim)
    TIME Thursday, 21 June 2018, 4:15 pm
    LOCATION Campus Technik, Seminarraum Mathematik 734 (Mathematik)
    ABSTRACT Preferential attachment models are self-reinforced growth models for complex networks. Recently, there has been much interest in developing PA models for networks embeded into some underlying geometric space. For one such model, proposed by Jacob and Mörters, I will discuss a Large Deviation principle for empirical vertex neighbourhoods and the asymptotics of the distance of two typical vertices in the giant component. The talk is based on joint work with Christian Hirsch (Aalborg).                                                    


 


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