activity
20202026
collaborators

7 papers

math.RT2026

Gluing parabolic character sheaves

Kostiantyn Tolmachov

We introduce and study the category of unipotent character sheaves on the non-degenerate locus of the Vinberg semigroup associated to a reductive group of adjoint type. We show tha…

math.RT2025

Generalized Markov traces and Jucys-Murphy elements

Kostiantyn Tolmachov, Heorhii Zhylinskyi

We give a simple construction of Markov traces for Iwahori-Hecke algebras associated with infinite series of crystallographic Coxeter groups. In types B and D it is new, and genera…

math.RT2024

On a t-exactness property of the Harish-Chandra transform

Roman Gonin, Andrei Ionov, Kostiantyn Tolmachov

Using hyperbolic localization, we identify the nearby cycles along the Vinberg degeneration with the composition of Radon and Harish-Chandra functors, both considered for the categ…

math.RT2024

Linear structure on a finite Hecke category in type A

Kostiantyn Tolmachov

For the group GL(n), we construct an action of the equivariant derived category of coherent sheaves on the Grothendieck-Springer resolution on a certain subcategory of a finite mon…

math.RT2023

Equivariant derived category of a reductive group as a categorical center

Roman Bezrukavnikov, Andrei Ionov, Kostiantyn Tolmachov +1

We prove that the adjoint equivariant derived category of a reductive group is equivalent to the appropriately defined monoidal center of the torus-equivariant version of the H…

math.RT2022

Exterior powers of a parabolic Springer sheaf on a Lie algebra

Roman Bezrukavnikov, Kostiantyn Tolmachov

We compute the exterior powers, with respect to the additive convolution on the general linear Lie algebra, of a parabolic Springer sheaf corresponding to a maximal parabolic subgr…

math.RT2020

Monodromic model for Khovanov-Rozansky homology

Roman Bezrukavnikov, Kostiantyn Tolmachov

We describe a new geometric model for the Hochschild cohomology of Soergel bimodules based on the monodromic Hecke category studied earlier by the first author and Yun. Moreover, w…