Vanishing of self-extensions over symmetric algebras
arXiv:1309.1088 · doi:10.1016/j.jpaa.2013.10.012
Abstract
We study self-extensions of modules over symmetric artin algebras. We show that non-projective modules with eventually vanishing self-extensions must lie in AR components of stable type . Moreover, the degree of the highest non-vanishing self-extension of these modules is determined by their quasilength. This has implications for the Auslander-Reiten Conjecture and the Extension Conjecture.