There will be 6 speakers, each will have 6 minutes for a blackboard talk and 2 minutes to answer questions from the audience. The line-up and titles are follows:
1. Thomas Nikolaus: The heart of cyclotomic spectra
2. Thomas Tony: Scalar curvature rigidity and higher index theory
3. Robin J. Sroka: On the homology of Temperley-Lieb algebras
4. Devarshi Mukherjee: Homological epimorphisms in geometric group theory
5. Phil Pützstück: Equivariant Picard Spectra
6. Arthur Bartels: Flow spaces
Angelegt am 10.10.2024 von Claudia Rüdiger
Geändert am 10.10.2024 von Claudia Rüdiger
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Oberseminar Differentialgeometrie: Roger Bielawski (Universität Hannover), Vortrag: QALF hyperkaehler manifolds of dihedral type
Monday, 14.10.2024 16:00 im Raum SRZ 214
There exists a natural higher dimensional generalisation of 4-dimensional ALF gravitational instantons of type A_n: the toric hyperkaehler manifolds of Bielawski and Dancer (2000). There are also known many examples of complete hyperkaehler manifolds, where the asymptotic behaviour of the metric should be described as being QALF of dihedral type. These include various monopole moduli spaces, Hilbert schemes of points on complex ALF surfaces, and, conjecturally,
Coulomb branches of N=4 supersymmetric quantum gauge theories.
In my talk, I shall present an approach to construction and classification of complete QALF hyperkaehler manifolds of dihedral type. This is a joint work with Lorenzo Foscolo.
Angelegt am 10.07.2024 von Sandra Huppert
Geändert am 26.08.2024 von Sandra Huppert
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17. John von Neumann Lecture: Prof. Dr. Lisa Sauermann (Universität Bonn): On three-term progression-free sets and related questions in additive combinatorics
Thursday, 17.10.2024 16:15 im Raum M4
Given some large positive integer N, what is the largest possible size of a subset of {1,...,N} which does not contain a three-term arithmetic progression (i.e. without three distinct elements x,y,z satisfying x+z=2y)? Similarly, given a prime p and a large positive integer n, what is the largest possible size of a subset of the vector space F_p^n which does not contain a three-term arithmetic progression (i..e without three distinct vectors x,y,z satisfying x+z=2y)? These are long-standing problems in additive combinatorics. This talk will explain the known bounds for these problems, give an overview of some of the proof techniques, and discuss additional applications of these techniques to other additive combinatorics problems.
David Kerr: Dynamical alternating groups and the McDuff property. Oberseminar C*-Algebren.
Tuesday, 08.10.2024 16:15 im Raum SRZ 216/217
In operator algebra theory central sequences have long played a significant role in addressing
problems in and around amenability, having been used both as a mechanism for producing various
examples beyond the amenable horizon and as a point of leverage for teasing out the finer structure
of amenable operator algebras themselves. One of the key themes on the von Neumann algebra side
has been the McDuff property for II_1 factors, which asks for the existence of noncommuting central
sequences and is equivalent, by a theorem of McDuff, to tensorial absorption of the unique
hyperfinite II_1 factor. We will show that, for a topologically free minimal action of a countable amenable
group on the Cantor set, the von Neumann algebra of the associated dynamical alternating group
is McDuff. This yields the first examples of simple finitely generated nonamenable groups for which
the von Neumann algebra is McDuff. This is joint work with Spyros Petrakos.
Angelegt am 07.10.2024 von Elke Enning
Geändert am 07.10.2024 von Elke Enning
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