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For positive integers m >= n >= p, we compute the GL_m x GL_n-equivariant description of the local cohomology modules of the polynomial ring S of functions on the space of m x n matrices, with support in the ideal of p x p minors. Our…

Algebraic Geometry · Mathematics 2015-07-24 Claudiu Raicu , Jerzy Weyman

In this paper, we investigate the properties of $A$-coherent and $A$-quasi-coherent sheaves within the framework of algebraic geometry over non-algebraically closed fields. We define an $\mathcal{O}_X$-module to be $A$-coherent (resp.…

Algebraic Geometry · Mathematics 2026-04-20 Hamet Seydi , Teylama Miabey

We present an explicit expression of the cohomology complex of a constructible sheaf of abelian groups on the small \'etale site of an irreducible curve over an algebraically closed field, when the torsion of the sheaf is invertible in the…

Algebraic Geometry · Mathematics 2026-02-16 Christophe Levrat

We introduce a sheaf-theoretic characterization of task solvability in general distributed computing models, unifying distinct approaches to message-passing models. We establish cellular sheaves as a natural mathematical framework for…

Distributed, Parallel, and Cluster Computing · Computer Science 2025-08-28 Stephan Felber , Bernardo Hummes Flores , Hugo Rincon Galeana

Let n be a positive integer, and let R be a finitely presented (but not necessarily finite dimensional) associative algebra over a computable field. We examine algorithmic tests for deciding (1) if every n-dimensional representation of R is…

Rings and Algebras · Mathematics 2007-05-23 Edward S. Letzter

We describe a software package for constructing minimal free resolutions of GL_n(Q)-equivariant graded modules M over Q[x_1, ..., x_n] such that for all i, the ith syzygy module of M is generated in a single degree. We do so by describing…

Commutative Algebra · Mathematics 2015-07-07 Steven V Sam

We present the design and implementation details of a geometric multigrid method on adaptively refined meshes for massively parallel computations. The method uses local smoothing on the refined part of the mesh. Partitioning is achieved by…

Numerical Analysis · Computer Science 2021-08-04 Thomas C. Clevenger , Timo Heister , Guido Kanschat , Martin Kronbichler

For a scheme X, we construct a sheaf C of complexes on X such that for every quasi-compact open subset U of X, C(U) is quasi-isomorphic to the Hochschild complex of the scheme U. Since C is moreover acyclic for taking sections on…

Algebraic Geometry · Mathematics 2007-07-19 Wendy Lowen

Let X be a separated finite type scheme over a noetherian base ring K. There is a complex C(X) of topological O_X-modules on X, called the complete Hochschild chain complex of X. To any O_X-module M - not necessarily quasi-coherent - we…

Algebraic Geometry · Mathematics 2007-05-23 Amnon Yekutieli

This article deals with computing the cohomology of Schur functors applied to tautological bundles on super Grassmannians. We show that in a range of cases, the cohomology is a free module over the cohomology of the structure sheaf and that…

Representation Theory · Mathematics 2026-02-03 Steven V Sam

In this paper, we introduce the concept of crossed module for Hom-Leibniz-Rinehart algebras. We study the cohomology and extension theory of Hom-Leibniz-Rinehart algebras. It is proved that there is one-to-one correspondence between…

Rings and Algebras · Mathematics 2022-12-27 Yanhui Bi , Danlu Chen , Tao Zhang

The purpose of this article is to show how one might compute the \'etale cohomology groups $H^p_{\acute{e}t}(X,G_m)$ in degrees $p=0$, $1$ and $2$ of a toric variety $X$ with coefficients in the sheaf of units. The method is to reduce the…

alg-geom · Mathematics 2008-02-03 Timothy J. Ford

We present a computer algorithm to explicitly compute the BGG resolution and its cohomology. We give several applications, in particular computation of various sheaf cohomology groups on flag varieties. An implementation of the algorithm is…

Representation Theory · Mathematics 2021-04-13 Nicolas Hemelsoet , Rik Voorhaar

The aim of this paper is twofold. First we prove a theorem of extension of sections of a coherent subquotient of a hermitian vector bundle on a complex analytic space with control of the norms, without any of the smoothness assumptions that…

Number Theory · Mathematics 2007-05-23 Hugues Randriam

This paper solves the problem of computing conformal structures of general 2-manifolds represented as triangle meshes. We compute conformal structures in the following way: first compute homology bases from simplicial complex structures,…

Graphics · Computer Science 2007-05-23 Xianfeng Gu , Shing-Tung Yau

We present an algorithm which, given a connected smooth projective curve $X$ over an algebraically closed field of characteristic $p>0$ and its Hasse--Witt matrix, as well as a positive integer $n$, computes all \'etale Galois covers of $X$…

Number Theory · Mathematics 2025-09-16 Christophe Levrat , Rubén Muñoz--Bertrand

A general method for establishing results over a commutative complete intersection local ring by passing to differential graded modules over a graded exterior algebra is described. It is used to deduce, in a uniform way, results on the…

Commutative Algebra · Mathematics 2010-03-30 Luchezar L. Avramov , Srikanth B. Iyengar

We contribute a new algebraic method for computing the orthogonal projections of a point onto a rational algebraic surface embedded in the three dimensional projective space. This problem is first turned into the computation of the finite…

Commutative Algebra · Mathematics 2020-04-10 Nicolás Botbol , Laurent Busé , Marc Chardin , Fatmanur Yildirim

Given a complex semisimple Lie algebra ${\mathfrak g}$ and a commutative ${\mathbb C}$-algebra $A$, let ${\mathfrak g}[A] = {\mathfrak g} \otimes A$ be the corresponding generalized current algebra. In this paper we explore questions…

Representation Theory · Mathematics 2015-11-03 Brian D. Boe , Christopher M. Drupieski , Tiago R. Macedo , Daniel K. Nakano

We study non-commutative projective lines over not necessarily algebraic bimodules. In particular, we give a complete description of their categories of coherent sheaves and show they are derived equivalent to certain bimodule species. This…

Representation Theory · Mathematics 2015-10-16 D. Chan , A. Nyman