English
Related papers

Related papers: $U$-Operators Acting on Harmonic Cocycles for $\ma…

200 papers

We outline an algorithm for computing Hecke operators on equivariant cohomology $H^\ast_{\Gamma_{\text{Sp}}}(X_{\text{Sp}};\rho)$ for the symplectic group $\text{Sp}_4(\mathbb{R})$. To do this, we define a new acyclic cell complex for…

Number Theory · Mathematics 2021-10-13 Dylan Galt , Mark McConnell

We develop and collect techniques for determining Hochschild cohomology of skew group algebras S(V)#G and apply our results to graded Hecke algebras. We discuss the explicit computation of certain types of invariants under centralizer…

Rings and Algebras · Mathematics 2007-05-23 Anne V. Shepler , Sarah Witherspoon

We introduce a natural Hopf algebra structure on the space of noncommutative symmetric functions which was recently studied as a vector space by Rosas and Sagan. The bases for this algebra are indexed by set partitions. We show that there…

Combinatorics · Mathematics 2016-11-08 Nantel Bergeron , Christophe Reutenauer , Mercedes Rosas , Mike Zabrocki

We consider compact locally symmetric spaces $\Gamma\backslash G/H$ where $G/H$ is a non-compact semisimple symmetric space and $\Gamma$ is a discrete subgroup of $G$. We discuss some features of the joint spectrum of the (commutative)…

Representation Theory · Mathematics 2021-04-13 Salah Mehdi , Martin Olbrich

Let $\Gamma$ be a torsion-free arithmetic group acting on its associated global symmetric space $X$. Assume that $X$ is of non-compact type and let $\Gamma$ act on the geodesic boundary $\partial X$ of $X$. Via general constructions in…

K-Theory and Homology · Mathematics 2017-09-19 Bram Mesland , Mehmet Haluk Sengun

We investigate the homology of a congruence subgroup Gamma of SL_3(Z) with coefficients in the Steinberg modules St(Q^3) and St(E^3), where E is a real quadratic field and the coefficients are Q. By Borel-Serre duality, H_0(Gamma, St(Q^3))…

Number Theory · Mathematics 2021-07-26 Avner Ash , Dan Yasaki

Let G be a reductive algebraic group associated to a self-adjoint homogeneous cone defined over Q, and let G' be an appropriate neat arithmetic subgroup of G. We present two algorithms to compute the action of the Hecke operators on the…

Number Theory · Mathematics 2007-05-23 Paul E. Gunnells , Mark McConnell

Let $\Gamma$ be a lattice in a locally compact group $G$. In earlier work, we used $KK$-theory to equip the $K$-groups of any $\Gamma$-$C^{*}$-algebra on which the commensurator of $\Gamma$ acts with Hecke operators. When $\Gamma$ is…

K-Theory and Homology · Mathematics 2018-12-26 Bram Mesland , Mehmet Haluk Sengun

A cohomological analysis of the renormalization freedom is performed in the Epstein-Glaser scheme on a flat Euclidean space. We study the deviation from commutativity between the renormalization and the action of all linear partial…

High Energy Physics - Theory · Physics 2007-12-17 Nikolay M. Nikolov

This is basically a summary of [Mu]. The focus of the paper is the explicit computation of Hecke operators for period functions. In particular we compute the matrix representations of the 2nd Hecke operator on period functions for the full…

Number Theory · Mathematics 2009-04-20 Tobias Mühlenbruch

For a finite group $\Gamma$, acting on a finite group $G,$ we find necessary conditions for which the first $\Gamma_0$-equivariant Hochschild cohomology of the group algebra $kG$ is non-trivial, where $k$ is a field of characteristic $p$…

K-Theory and Homology · Mathematics 2026-05-21 Andrada Pojar , Constantin-Cosmin Todea

In this paper, we study the Hochschild cohomology of diagrams of algebras introduced by Gerstenhaber and Schack and provide computations for filtrations of incidence algebras. Our aims are threefold: firstly, we revisit and explore the…

Algebraic Topology · Mathematics 2025-12-19 Luigi Caputi , Francesco Vaccarino

We extend the computations in our prior work to find the cohomology in degree five of a congruence subgroup Gamma of SL_4(Z) with coefficients in Sym^g(K^4), twisted by a nebentype character eta, along with the action of the Hecke algebra.…

Number Theory · Mathematics 2024-05-14 Avner Ash , Paul E. Gunnells , Mark McConnell

Let $\Gamma=\Gamma(N)$ be a principal congruence subgroup of $SL_2(\mathbb Z)$. In this paper, we extend the theory of modular Hecke algebras due to Connes and Moscovici to define the algebra $\mathcal Q(\Gamma)$ of quasimodular Hecke…

Number Theory · Mathematics 2015-09-04 Abhishek Banerjee

In this paper we obtain explicit formulas for the traces of Hecke operators on spaces of cusp forms in certain instances related to arithmetic triangle groups. These expressions are in terms of hypergeometric character sums over finite…

Number Theory · Mathematics 2025-03-05 Jerome W. Hoffman , Wen-Ching Winnie Li , Ling Long , Fang-Ting Tu

Let G be a torsion-free finite-index subgroup of SL(n,Z) or GL(n,Z), and let d be the cohomological dimension of G. We present an algorithm to compute the eigenvalues of the Hecke operators on the integral cohomology of degree d-1 for n =…

Number Theory · Mathematics 2016-09-07 Paul E. Gunnells

We prove the $\Gamma$-convergence of sequences of differentially constrained, random integral functionals of the form \begin{equation*} \int_{U} f\Big(\omega, x/\varepsilon, \mathbb{A} u\Big) \mathrm{d} x \end{equation*} for the class of…

Analysis of PDEs · Mathematics 2023-08-08 Piotr Wozniak

We consider finite groups acting on quantum (or skew) polynomial rings. Deformations of the semidirect product of the quantum polynomial ring with the acting group extend symplectic reflection algebras and graded Hecke algebras to the…

Rings and Algebras · Mathematics 2019-08-15 Viktor Levandovskyy , Anne V. Shepler

Let $G$ be a semi-simple real Lie group of real rank one and $\Gamma$ be a discrete subgroup in $G$ such that $\Gamma \backslash G$ has finite volume. We introduce a new group $C^*$-algebra $C^*_r(G, \Gamma)$, which provides a natural…

K-Theory and Homology · Mathematics 2025-07-30 Yanli Song

In this article we investigate the action of (ramified and unramified) Hecke operators on automorphic forms for the function field of the projective line defined over a finite field and for the group GL_2. We first compute the dimension of…

Number Theory · Mathematics 2024-06-19 Roberto Alvarenga , Nans Bonnel