Organizers

dr hab. Andrzej Weber, prof. UW
dr Krzysztof Ziemiański

Information

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

Home page

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

Research fields

Algebraic Topology

List of talks

Oct. 26, 2021, 4:30 p.m.
Magdalena Zielenkiewicz (MIMUW)
Rozkłady komórkowe dla Grassmannianów kołczanowych
Mając dany kołczan i jego reprezentację, grassmannian kołczanowy parametryzuje jej podreprezentacje ustalonego (wektora) wymiaru. Niektóre grassmanniany kołczanowe posiadają rozkład na komórki afiniczne. Opowiem o tym, co wiadomo - które grassmanniany kołczanowe dopuszczają taki rozkład, i …
Oct. 19, 2021, 4:30 p.m.
Bob Oliver (LAGA, Paris)
A Krull-Remak-Schmidt theorem for fusion systems
The Krull-Remak-Schmidt theorem, when restricted to finite groups, implies that every finite group factorizes as a product of indecomposable subgroups which areunique up to isomorphism. But the theorem actually says much more. For example, as …
Oct. 12, 2021, 4:30 p.m.
Jakub Koncki (MIMUW)
Boundness of motivic Chern class
I will define the equivariant motic Chern class. I will show that it satisfies certain smallness condition. This condition allows to compare the motivic Chern class with the stable envelopes.
June 8, 2021, 4:30 p.m.
Jarek Kędra (University of Aberdeen)
On quasimorphisms invariant under automorphisms
Quasimorphisms comprise a good function theory on groups and many groups admits an abundance of them. It was recently discovered by Brandenbursky and Marcinkowski that the free group on two generators admits a quasimorphism that …
May 25, 2021, 4:30 p.m.
Agnieszka Bodzenta (MIMUW)
Ringel duality
Quasi-hereditary algebras and, more generally, highest weight categories first appeared as categories of perverse sheaves on a stratified topological space. Another example is the category O of Bernstein-Bernstein-Gelfand. In the talk I will recall the …
May 18, 2021, 4:30 p.m.
Adam Przeździecki (SGGW)
Set-theoretic problems in constructing localizations
https://www.mimuw.edu.pl/~aweber/STA/AP-lokalizacja.pdf
- file
May 11, 2021, 4:30 p.m.
Maria Yakerson (ETH Zürich)
Algebraic and hermitian K-theory in motivic homotopy theory
Algebraic K-theory space, as a motivic space, has a known geometric model given by (Z copies of) the infinite Grassmannian. In the new geometric model that we offer, the infinite Grassmannian is replaced by the …
April 27, 2021, 4:30 p.m.
László Fehér (Eötvös Loránd University, Budapest)
Plücker formulas and motivic classes of coincident root loci
https://www.mimuw.edu.pl/~aweber/STA/plucker-abstract.pdf
- file
April 20, 2021, 4:30 p.m.
Akos Matszangosz (Renyi Institute (Budapeszt))
Cohomology rings of real flag manifolds
The cohomology ring of a complex (partial) flag manifold has two classical descriptions; a topological one (via characteristic classes) and a geometric one (via Schubert classes). Similar descriptions are well-known for real flag manifolds X …
April 13, 2021, 4:30 p.m.
Tomasz Maszczyk (UW)
The Hochschild cohomology for abstract convexity and the Shannon entropy
The Shannon entropy was introduced as a statistical measure of the information loss but appears in other fields of mathematics as well. We will start from the survey of the Faddeev algebraic characterization theorem and …
March 30, 2021, 4:30 p.m.
Denis Nardin (Regensburg)
Hermitian K-theory of rings
The theory of quadratic and symmetric bilinear forms over rings has traditionally been more developed when 2 is invertible in the ring. In this talk we will present a new approach allowing to put some …
March 23, 2021, 4:30 p.m.
Tibor Macko (Slovak Academy of Sciences)
Cobordisms of quadratic chain complexes
A fundamental problem in surgery theory is to decide whether a given finite CW-complex X of dimension n>=5 satisfying Poincare duality is homotopy equivalent to a topological manifold. In the classical surgery theory due to …
March 16, 2021, 4:30 p.m.
Bruno Stonek (IMPAN)
Tensors of Thom spectra with spaces: generalizing Mahowald's Thom isomorphism
The topological Hochschild homology (THH) of a commutative ring spectrum R can be expressed as a tensor with a circle. More generally, one can tensor R with any space X. In this talk we will …
March 9, 2021, 4:30 p.m.
Patryk Jaśniewski (UW)
Homological structure of the category of strict polynomial functors of prime degree p
https://www.mimuw.edu.pl/~aweber/STA/21.03.09.pdf
Jan. 26, 2021, 4:30 p.m.
Andrzej Szczepański (UG)
Combinatorial Hantzsche-Wendt group
Let n\in N. By a combinatorial Hantzsche-Wendt group we shall understand a finite presented group G_n = {x_1, ..., x_n | x_i^{-1} x_j^2 x_i x_j^2 \forall i\neq j}. During a talk I will present properties …