Robert Cass

activity

20192026

most citedCentral elements in affine mod

p

Hecke algebras via perverse

F_{p}

-sheaves

4 citations · 11 across the 9 of their papers we have counts for

collaborators

9 papers

math.RT2026

Kloosterman sheaves and Bessel functions for generic principal series of finite groups

Robert Cass, Miao Pam Gu, Elad Zelingher

Let $G$ be a quasi-split reductive group over a finite field and let $G^$ be the Langlands dual group. Assuming the derived subgroup of $G$ is almost simple, we use techniques from…

math.AG2026

Exponential motives on the affine Grassmannian

Robert Cass, Thibaud van den Hove, Jakob Scholbach

We develop a notion of exponential motives on general prestacks equipped with a $G_{a}$ -action, and compare them with Whittaker motives via Gaitsgory's Kirillov model. We th…

math.AG2025

Mod $p$ sheaves on Witt flags

Robert Cass, João Lourenço

We characterize Cohen--Macaulay and $φ$ -rational perfect schemes in terms of their perverse étale mod $p$ sheaves. Using inversion of adjunction, we prove that sufficiently small S…

math.AG2024

Central motives on parahoric flag varieties

Robert Cass, Thibaud van den Hove, Jakob Scholbach

We construct a refinement of Gaitsgory's central functor for integral motivic sheaves, and show it preserves stratified Tate motives. Towards this end, we develop a reformulation o…

math.NT2022★ 1 cited

Geometrization of the Satake transform for mod $p$ Hecke algebras

Robert Cass, Yujie Xu

We geometrize the mod $p$ Satake isomorphism of Herzig and Henniart-Vignéras using Witt vector affine flag varieties for reductive groups in mixed characteristic. We deduce this as…

math.AG2022★ 2 cited

The geometric Satake equivalence for integral motives

Robert Cass, Thibaud van den Hove, Jakob Scholbach

We prove the geometric Satake equivalence for mixed Tate motives over the integral motivic cohomology spectrum. This refines previous versions of the geometric Satake equivalence f…

math.AG2021

Constant term functors with $F_{p}$ -coefficients

Robert Cass, Cédric Pépin

We study the constant term functor for $F_{p}$ -sheaves on the affine Grassmannian in characteristic $p$ with respect to a Levi subgroup. Our main result is that the constant…

math.AG2020★ 4 cited

Central elements in affine mod $p$ Hecke algebras via perverse $F_{p}$ -sheaves

Robert Cass

Let $G$ be a split connected reductive group over a finite field of characteristic $p > 2$ such that $G_{der}$ is absolutely almost simple. We give a geometric construction of…

math.AG2019★ 4 cited

Perverse $F_{p}$ -sheaves on the affine Grassmannian

Robert Cass

For a reductive group over an algebraically closed field of characteristic $p > 0$ we construct the abelian category of perverse $F_{p}$ -sheaves on the affine Grassmannian t…

Kloosterman sheaves and Bessel functions for generic principal series of finite groups

Exponential motives on the affine Grassmannian

Mod p sheaves on Witt flags

Central motives on parahoric flag varieties

Geometrization of the Satake transform for mod p Hecke algebras

The geometric Satake equivalence for integral motives

Constant term functors with Fp​-coefficients

Central elements in affine mod p Hecke algebras via perverse Fp​-sheaves

Perverse Fp​-sheaves on the affine Grassmannian

Mod $p$ sheaves on Witt flags

Geometrization of the Satake transform for mod $p$ Hecke algebras

Constant term functors with $F_{p}$ -coefficients

Central elements in affine mod $p$ Hecke algebras via perverse $F_{p}$ -sheaves

Perverse $F_{p}$ -sheaves on the affine Grassmannian