Almost fine gradings on algebras and classification of gradings up to isomorphism

Autor:	Elduque, Alberto, Kochetov, Mikhail
Rok vydání:	2023
Předmět:	Mathematics - Rings and Algebras Primary 17A01 Secondary 17A36 17B70 16W50 20G07
Druh dokumentu:	Working Paper
Popis:	We consider the problem of classifying gradings by groups on a finite-dimensional algebra $A$ (with any number of multilinear operations) over an algebraically closed field. We introduce a class of gradings, which we call almost fine, such that every $G$-grading on $A$ is obtained from an almost fine grading on $A$ in an essentially unique way, which is not the case with fine gradings. For abelian groups, we give a method of obtaining all almost fine gradings if fine gradings are known. We apply these ideas to the case of semisimple Lie algebras in characteristic $0$: to any abelian group grading with nonzero identity component, we attach a (possibly nonreduced) root system and, in the simple case, construct an adapted grading by this root system. Comment: 17 pages
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2308.07230 Zobrazit plný text záznamu View this record from Arxiv