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Weekly research seminar
List of talks
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Jan. 8, 2020, 4:15 p.m.
Piotra Suwary (MIT)
Floer Homology via Semi-Infinite Dimensional Cycles
The basic idea behind Floer homology is to define homology groups of a functional on an infinite-dimensional space by mimicking the construction of Morse homology for finite dimensional manifolds. Various flavors of Floer homology have …
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Dec. 11, 2019, 4:15 p.m.
Piotr Nowak (IMPAN)
T) dla grup automorfizmów grup wolnyc (Własność)
Celem wykładu będzie udowodnienie twierdzenia o tym, że Aut(F_n), grupa automorfizmów grupy wolnej na n generatorach, ma własność (T) Kazhdana dla n>4. Własność (T) dla grupy G jest równoważna znikaniu kohomologii H^1(G,\pi) o współczynnikach w …
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Dec. 4, 2019, 4:15 p.m.
Piotr Achinger (IMPAN)
Condensed mathematics, after Clausen and Scholze
Condensed mathematics is an over-arching framework for dealing with topological groups, rings, and modules recently proposed by Clausen and Scholze. A "condensed set" is, modulo set-theoretic issues, a sheaf on the category of profinite sets, …
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Nov. 13, 2019, 4:15 p.m.
Andrzej Szczepański (UG)
za Mariusem Dadarlatem (Spajające grupy Bieberbacha)
C* - algebrę A nazywamy spajajacą (connective) o ile istnieje *-monomorfizm z A do pewnej "uniwersalnej" C*-algebry. C* - algebrę grupową C*(G) nazywamy spajajacą o ile jej ideał augumentacji (jadro odwzorowania C*(G) ----> \C) jest …
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Nov. 6, 2019, 4:15 p.m.
Andrzej Weber (UW)
O ekwiwariantnych eliptycznych kohomologiach
Przypomnę klasyczne eliptyczne kohomologie, tak jak były definiowane w atykule Graema Segala "Elliptic Cohomology" z 1988-go roku i porównam z nowym podejściem opisanym w pracy Nory Ganter "The elliptic Weyl character formula", arXiv:1206.0528.
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Oct. 30, 2019, 4:15 p.m.
Jkub Koncki (UW)
Motivic Chern Classes Of Configuration Spaces
We calculate equivariant motivic Chern class for configuration space of smooth variety and space of vectors with different directions. We prove formulas for generating series of these classes. We generalize localization theorems results about BB-decomposition …
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Oct. 16, 2019, 4:15 p.m.
Wojciech Politarczyk (UW)
Non-slice linear combinations of iterated torus knots
Algebraic knots are knots which arise as links of isolated singularities of complex curves. Lee Rudolph conjectured that the set of algebraic knots is linearly independent in the smooth knot concordance group. Rudolph’s conjecture is …
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July 4, 2019, 2:15 p.m.
Józef Przytycki (George Washington University)
Wyznaczniki Grama motywowane teoria węzłów
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June 11, 2019, 4:15 p.m.
Łukasz Grabowski (Lancaster University)
Approximation of groups with respect to the rank metric
Abstract: I'll talk about an ongoing joint work with Gabor Elek about approximation of groups with respect to the rank metric. The basic question is the following variant of the Halmos problem about commuting matrices: …
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June 4, 2019, 4:15 p.m.
Thomas Koberda (University of Virginia)
Algebra versus regularity for group actions on one-manifolds
JOINT WITH SIMONS SEMESTER I will survey some results concerning the algebraic structure of finitely generated groups which admit faithful actions on compact one-manifolds. I will concentrate on continuous, C^1 , and C^2 actions, and …
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May 28, 2019, 4:15 p.m.
Genevieve Walsh (Tufts University)
Incoherence of many free by free groups
A group is coherent if every finitely generated subgroup is finitely presented. Free by cyclic groups are known to be coherent by work of Feighn and Handel. We show that many free by free groups …
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May 7, 2019, 4:15 p.m.
Mahan Mj (Tata Institute of Fundamental Research)
Coarse Extrinsic Geometry and surface-by-free groups
JOINT WITH SIMONS SEMESTER The notion of distortion of finitely generated subgroups H of finitely generated groups G, introduced by Gromov, is a first step towards studying extrinsic geometry of subgroups in the coarse setup. …
