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In this paper, we introduce the notion of BiHom-Lie conformal superalgebras. We develop its representation theory and define the cohomology group with coefficients in a module. Finally, we introduce conformal derivations of BiHom-Lie…

Representation Theory · Mathematics 2020-09-09 Taoufik Chtioui

We compute the continuous bounded cohomology of the full automorphism groups of regular trees in all positive degrees, with coefficients arising from any irreducible continuous unitary representations. To the author's knowledge, this seems…

Group Theory · Mathematics 2026-01-08 Cunyuan Zhao

We introduce the notion of Lie-Yamaguti algebra bundle, define its cohomology groups with coefficients in a representation and show that such bundles appeared naturally from geometric considerations in the work of M. Kikkawa, which…

Rings and Algebras · Mathematics 2025-05-15 Saikat Goswami , Goutam Mukherjee

Lecture notes. Introduction to the cohomology of algebras, Lie algebras, Lie bialgebras and quantum groups. Contains a new derivation of the classification of classical r-matrices in terms of deformation cohomology, and a calculation of the…

q-alg · Mathematics 2014-05-27 Christian Fronsdal

We introduce a new class of algebras over discrete valuation rings, called Kleinian 4-rings, which generalize the group algebra of the Kleinian 4-group. For these algebras we describe the lattices and their cohomologies. In the case of…

Representation Theory · Mathematics 2022-04-28 Yuriy A. Drozd

The goal of this paper is to show that the cohomology of compact unitary Shimura varieties is concentrated in the middle degree and torsion-free, after localizing at a maximal ideal of the Hecke algebra satisfying a suitable genericity…

Number Theory · Mathematics 2015-11-10 Ana Caraiani , Peter Scholze

Bihom-associative algebras have been recently introduced in the study of group hom-categories. In this paper, we introduce a Hochschild type cohomology for bihom-associative algebras with suitable coefficients. The underlying cochain…

Rings and Algebras · Mathematics 2020-08-27 Apurba Das

Given an arrangement of subtori of arbitrary codimension in a torus, we compute the cohomology groups of the complement. Then, using the Leray spectral sequence, we describe the multiplicative structure on the graded cohomology. We also…

Algebraic Topology · Mathematics 2023-03-08 Luca Moci , Roberto Pagaria

The integral singular cohomology ring of the Grassmann variety parametrizing $r$-dimensional subspaces in the $n$-dimensional complex vector space is naturally an irreducible representation of the Lie algebra of all the $n\times n$ matrices…

Algebraic Geometry · Mathematics 2019-02-12 Letterio Gatto , Parham Salehyan

In this paper, we define and study (co)homology theories of a compatible associative algebra $A$. At first, we construct a new graded Lie algebra whose Maurer-Cartan elements are given by compatible associative structures. Then we define…

Rings and Algebras · Mathematics 2021-07-21 Taoufik Chtioui , Apurba Das , Sami Mabrouk

Conformal algebra is an axiomatic description of the operator product expansion of chiral fields in conformal field theory. On the other hand, it is an adequate tool for the study of infinite-dimensional Lie algebras satisfying the locality…

Quantum Algebra · Mathematics 2009-10-31 Bojko Bakalov , Victor G. Kac , Alexander A. Voronov

Complexified spacetime algebra is defined as the geometric (Clifford) algebra of spacetime with complex coefficients, isomorphic $\mathcal{G}_{1,4}$. By resorting to matrix representation by means of Dirac-Pauli gamma matrices, the paper…

General Mathematics · Mathematics 2007-05-23 Jose B. Almeida

We give a new proof of a Theorem of Vogan which classify the cohomological representations of a real semisimple Lie group $G$ which are isolated in the unitary dual of $G$. We investigate the same question in the automorphic dual, and…

Representation Theory · Mathematics 2007-05-23 N. Bergeron

We give formulas for the products of classes of Schubert varieties in the quantum cohomology rings of Grassmannians, in terms of the combinatorics of partitions and tableaux.

alg-geom · Mathematics 2008-02-03 Aaron Bertram , Ionut Ciocan-Fontanine , William Fulton

Higher order group cohomology is defined and first properties are given. Using modular symbols, an Eichler-Shimura homomorphism is constructed mapping spaces of higher order cusp forms to higher order cohomology groups.

Number Theory · Mathematics 2014-09-04 Anton Deitmar

Locally trivial bundles of $C^*$-algebras with fibre $D \otimes \mathcal{K}$ for a strongly self-absorbing $C^*$-algebra $D$ over a finite CW-complex $X$ form a group $E^1_D(X)$ that is the first group of a cohomology theory $E^*_D(X)$. In…

Operator Algebras · Mathematics 2026-01-08 Marius Dadarlat , James E. McClure , Ulrich Pennig

The study of the homology of diagram algebras has emerged as an interesting and important field. In many cases, the homology of a diagram algebra can be identified with the homology of a group. In this paper we have two main aims. Firstly,…

Algebraic Topology · Mathematics 2024-12-20 Andrew Fisher , Daniel Graves

This paper is a contribution to the general problem of giving an explicit description of the basic locus in the reduction modulo $p$ of Shimura varieties. Motivated by \cite{Vollaard-Wedhorn} and \cite{Rapoport-Terstiege-Wilson}, we…

Algebraic Geometry · Mathematics 2013-11-26 Ulrich Goertz , Xuhua He

In [Inventiones mathematicae, 184 (2011)], Vollaard and Wedhorn defined a stratification on the special fiber of the unitary unramified PEL Rapoport-Zink space with signature $(1,n-1)$. They constructed an isomorphism between the closure of…

Representation Theory · Mathematics 2022-11-29 Joseph Muller

We prove explicit and elementary formulas for the group homology and cohomology of a finite group with coefficients in any module. We describe in elementary terms the cohomology algebra $H^*(G,k)$ as a graded algebra for a finite group $G$…

Group Theory · Mathematics 2015-07-16 Sergei O. Ivanov , Nikolay N. Mostovsky