Applications of stratifying systems to the finitistic dimension

Abstract

Given an Ext-injective stratifying system of A-modules (theta, (Y) over bar, less than or similar to) satisfying that the projective dimension of Y is finite, we prove that the finitistic dimension of the algebra A is equal to the finitistic dimension of the category I(theta) = {X is an element of mod Lambda : Ext(Lambda)(1) (-, X)vertical bar(F(theta)) = 0}. Moreover, using the theory of stratifying systems we obtain bounds for the finitistic dimension of A. In particular, we get the optimal bound 2n - 2 for the finitistic dimension of a standardly stratified algebra with n simples. (c) 2005 Elsevier B.V. All rights reserved.