Dual F-signature of special Cohen-Macaulay modules over cyclic quotient surface singularities
arXiv:1311.5967
Abstract
The notion of -signature is defined by C. Huneke and G. Leuschke and this numerical invariant characterizes some singularities. This notion is extended to finitely generated modules and called dual -signature. In this paper, we determine the dual -signature of a certain class of Cohen-Macaulay modules (so-called "special") over cyclic quotient surface singularities. Also, we compare the dual -signature of a special Cohen-Macaulay module with that of its Auslander-Reiten translation. This gives a new characterization of the Gorensteiness.
14 pages, to appear in J. Commut. Algebra, v3: improved proofs of theorems, v2: minor changes