Maximal Cohen-Macaulay modules that are not locally free on the punctured spectrum
Abstract
We say that a Cohen-Macaulay local ring has finite -representation type if there exist only finitely many isomorphism classes of indecomposable maximal Cohen-Macaulay modules that are not locally free on the punctured spectrum. In this paper, we consider finite -representation type from various points of view, relating it with several conjectures on finite/countable Cohen-Macaulay representation type. We prove in dimension one that the Gorenstein local rings of finite -representation type are exactly the local hypersurfaces of countable -representation type, that is, the hypersurfaces of type and . We also discuss the closedness and dimension of the singular locus of a Cohen-Macaulay local ring of finite -representation type.
Keywords
Cite
@article{arxiv.1903.03287,
title = {Maximal Cohen-Macaulay modules that are not locally free on the punctured spectrum},
author = {Toshinori Kobayashi and Justin Lyle and Ryo Takahashi},
journal= {arXiv preprint arXiv:1903.03287},
year = {2020}
}
Comments
24 pages. Minor corrections made throughout