### Conferences - Seminars

26APR

13:00-14:00
MA A3 30

## Groups acting on rooted trees and representations on the boundary

Every action of a group on a rooted tree induces an action on the boundary of the tree. This action yields various representations of the group on spaces of functions on the boundary. In this talk we discuss the structure of such representations. After reviewing of the basic concepts, we will introduce locally 2-transitive actions ...
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By Steffen Kionke (KIT)

27APR

15:15-16:00
MA A1 10

## A Bayesian General Linear Modeling Approach to Cortical Surface fMRI Data Analysis

By Ass. Prof. David Bolin, Chalmers University of Technology

01MAY

10:15-11:30
CM 1 113

## Topology Seminar: C*-superrigidiity of nilpotent groups

It is a classical problem to recover a discrete group from various rings or algebras associated with it, such as the integral group ring (cf. the Whitehead group and the Whitehead torsion). By analogy, in an operator algebraic framework we want to recover torsion-free groups from certain topological completions of the complex group ring, such ...
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By Sven Raum (EPFL)

08MAY

10:15-11:15
CM 1 113

## Topology Seminar: Stratified homotopy theory

Stratified spaces appear as natural objects in singularity theory. Goresky and MacPherson introduced intersection cohomology to extend cohomological properties of closed manifolds to stratified spaces, and it proved to be a powerful tool to study those objects. However, intersection cohomology is not homotopy invariant, rather it is invariant with respect to homotopies that "preserve" the ...
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By Sylvain Douteau (Université de Picardie)

15MAY

09:15-10:15
CM 1 113

## Topology Seminar: Combinatorial models for stable homotopy theory

We will recall the definition of dendroidal sets as a generalization of simplicial sets, and present the connection (Quillen equivalence) to connective spectra which gives a factorization of the so-called K-theory spectrum functor from symmetric monoidal categories to spectra. We will present a common generalization of two results of Thomason: 1) posets model all homotopy ...
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By Matija Bašić (University of Zagreb)

15MAY

By Dr Tommaso TADDEI (Université Pierre et Marie Curie, FR)

24MAY

15:15-16:00
MA A1 10

## Learning determinantal point processes

Statistics seminar
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By Prof. Philippe Rigollet, MIT

01JUN

By Ass. Prof. Patrick Rubin-Declanchy, University of Bristol

04JUN

08JUN

08JUN

09:00-17:00
BI A0 448

## Ideals and exceptional sets in Polish spaces

Exceptional sets play an important role in numerous branches of mathematics, for instance in measure theory, topology, harmonic and complex analysis, Banach space theory, algebraic geometry, combinatorics, probability and ergodic theory, set theory and descriptive set theory, just to mention a few. Exceptional sets describe notions of smallness from various points of view, some notable ...
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18JUN

22JUN

22JUN

09:00-17:00
BI A0 448

## Descriptive set theory conference

This is the last conference of the semester and will be of a more general nature than the earlier more specialized conferences and workshops of the program. It will cover broad aspects of descriptive set theory and its connections with other areas of mathematics.
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21JUN

17:15-18:15
BI A0 448

## Professeur Slawomir Solecki Bernoulli Lecture - Compact Spaces and Logic

Fraïssé theory is a method in classical Model Theory of producing canonical limits of certain families of finite structures. For example, the random graph is the Fraïssé limit of the family of all finite graphs. It turns out that this method can be dualized, with the dualization producing projective Fraïssé limits, and applied to the ...
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By Slawomir Solecki (Cornell University)

16JUL

27JUL

27JUL

09:00-17:00
BI A0 448

## Introduction to Partition Functions

A mix of introductory lectures and research talks on partition functions and techniques for their computation, including methods such as Markov chains, correlation decay, belief propagation and convex optimization.
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01OCT

05OCT

05OCT

09:00-17:00
BI A0 448

## Theoretical Challenges in Partition Functions

The goal of this workshop is to find translations and connections between various approaches to compute partition functions and, at the same time, advance the state-of-the-art in each.
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12NOV

16NOV

16NOV

09:00-17:00
BI A0 448

## Applications of Partition Functions

The goal of this workshop is to discuss the wide set of practical and theoretical applications of the computability of partition functions and address the challenges that arise.
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