Computing Direct Sum Decompositions

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Mallory, Devlin, Sayrafi, Mahrud
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866917539072704512
author Mallory, Devlin
Sayrafi, Mahrud
author_facet Mallory, Devlin
Sayrafi, Mahrud
contents We describe and prove correctness of two practical algorithms for finding indecomposable summands of finitely generated modules over a finitely generated k-algebra R. The first algorithm applies in the (multi)graded case, which enables the computation of indecomposable summands of coherent sheaves on subvarieties of toric varieties (in particular, for varieties embedded in projective space); the second algorithm applies when R is local and k is a finite field, opening the door to computing decompositions in singularity theory. We also present multiple examples, including some which present previously unknown phenomena regarding the behavior of summands of Frobenius pushforwards (including in the non-graded case) and syzygies over Artinian rings.
format Preprint
id arxiv_https___arxiv_org_abs_2412_19799
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Computing Direct Sum Decompositions
Mallory, Devlin
Sayrafi, Mahrud
Commutative Algebra
Algebraic Geometry
16D70, 14F06, 13A35
We describe and prove correctness of two practical algorithms for finding indecomposable summands of finitely generated modules over a finitely generated k-algebra R. The first algorithm applies in the (multi)graded case, which enables the computation of indecomposable summands of coherent sheaves on subvarieties of toric varieties (in particular, for varieties embedded in projective space); the second algorithm applies when R is local and k is a finite field, opening the door to computing decompositions in singularity theory. We also present multiple examples, including some which present previously unknown phenomena regarding the behavior of summands of Frobenius pushforwards (including in the non-graded case) and syzygies over Artinian rings.
title Computing Direct Sum Decompositions
topic Commutative Algebra
Algebraic Geometry
16D70, 14F06, 13A35
url https://arxiv.org/abs/2412.19799