Cotygodniowe seminarium badawcze
2021-06-08, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
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 is invariant under all automorphisms of F_2. I will present a more...
2021-05-25, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
Agnieszka Bodzenta (MIMUW)
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 classical Ringel duality for highest weig...
2021-05-18, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
Adam Przeździecki (SGGW)
Set-theoretic problems in constructing localizations
https://www.mimuw.edu.pl/~aweber/STA/AP-lokalizacja.pdf ...
2021-05-11, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
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 Hilbert scheme of the infinite affine space, stabilized with respect to degree. A...
2021-04-27, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
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 ...
2021-04-20, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
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 with mod 2 coefficients. In this talk I will discuss some ...
2021-04-13, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
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 the fundamental information functional equation after Tverberg, Kendall, Lee. Ne...
2021-03-30, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
Denis Nardin (Regensburg)
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 order in the various flavours of quadratic forms one could define when 2 is not invertible, and we ...
2021-03-23, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
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 Browder-Novikov-Sullivan-Wall this question is answered by a two-stage ob...
2021-03-16, godz. 16:30, Zoom: 892 1108 9551 Password - type the number equal to rk(H^2((S^1)^{200};Z))
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 introduce this construction, then look at the case where R is a Thom spectrum Mf of an E_infty map G\to Pic(R...