Organizers

Information

Wednesdays, 10:30 a.m. , room: 4070

Home page

http://duch.mimuw.edu.pl/~aweber/STA/

Research fields

Algebraic Topology

List of talks

Nov. 13, 2019, 4:15 p.m.
Andrzej Szczepański (UG)
za Mariusem Dadarlatem
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 …
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.
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 …
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 …
July 4, 2019, 2:15 p.m.
Józef Przytycki (George Washington University)
Wyznaczniki Grama motywowane teoria węzłów
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: …
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 …
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 …
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. …
April 30, 2019, 4:15 p.m.
Marcin Sabok (McGill University, IMPAN)
On a conjecture of Gardner
JOINT WITH SIMONS SEMESTER In 1925, Tarski asked if a disc in the plane and a square of the same area are equidecomposable, i.e. if the disc can be partitioned into finitely many pieces which …
April 16, 2019, 4:15 p.m.
Michael W. Davis (Ohio State University)
The action dimension of a discrete group
Colloquim joint with Simons Semester A space is called a K(G,1) if its fundamental group is G and if its universal cover is contractible. The geometric dimension of G is the smallest dimension of a …
April 2, 2019, 4:15 p.m.
Pierre Pansu (Universite Paris-Sud)
Aspects of geometric group theory: growth, isoperimetry, Lp-cohomology
SIMONS SEMESTER COLLOQUIUM The growth and isoperimetry of finitely generated groups have been among its early interests. We shall show how they lead to today’s cohomological methods, notions of negative curvature and rigidity problems. https://www.impan.pl/en/activities/banach-center/conferences/19simons-xi
March 26, 2019, 4:15 p.m.
Michał Lech (MIMUW)
Grupa monodromii osobliwości i automorfizmy diagramów Dynkina
Feb. 26, 2019, 4:15 p.m.
Grzegorz Banaszak (UAM)
Algebraic Sato-Tate group for motives
In my talk I will explain the notion of equidistibution, in particular the Sato-Tate conjecture concerning the equidistribution of Frobenius elements in l-adic representations. In particular I will show how to apply the motivic Galois …
Jan. 22, 2019, 4:15 p.m.
Rafał Lutowski (UG)
Spin struktury płaskich rozmaitości typu diagonalnego
Zaprezentujemy czysto kombinatoryczny opis klas Stiefela-Whitneya płaskich rozmaitości z diagonalną reprezentacją holonomii. Używając tego opisu, dla każdej liczby całkowitej d większej od 1 skonstruujemy orientowalną płaską rozmaitość z elementarną abelową grupą holonomii rangi d, której …