Representation schemes and rigid maximal Cohen–Macaulay modules

H Dao, I Shipman - Selecta Mathematica, 2017 - Springer
Let kk be an algebraically closed field and A be a finitely generated, centrally finite,
nonnegatively graded (not necessarily commutative) k k-algebra. In this note we construct a …

Free Resolutions for deformations of maximal Cohen-Macaulay modules

L O'Carroll, D Popescu - Communications in Algebra, 2000 - Taylor & Francis
Let K be a field and sets of indetorminates, and f∈ k [[x]] g∈ k [[Y]] two non-zero formal
power series with f∈(x) g∈(Y). Set and suppose that δg is a (y)-primary ideal (eg, if char K …

Cohomologically full rings

H Dao, A De Stefani, L Ma - … Mathematics Research Notices, 2021 - academic.oup.com
Inspired by a question raised by Eisenbud–Mustaţă–Stillman regarding the injectivity of
maps from modules to local cohomology modules and the work by the third author with …

[HTML][HTML] Degenerations over (A∞)-singularities and construction of degenerations over commutative rings

N Hiramatsu, R Takahashi, Y Yoshino - Journal of Algebra, 2019 - Elsevier
We give a necessary condition of degeneration via matrix representations, and consider
degenerations of indecomposable Cohen–Macaulay modules over hypersurface …

[HTML][HTML] Connections on modules over singularities of finite CM representation type

E Eriksen, TS Gustavsen - Journal of pure and Applied Algebra, 2008 - Elsevier
Let A be a commutative k-algebra, where k is an algebraically closed field of characteristic 0,
and let M be an A-module. We consider the following question: Under what conditions is it …

Finite and countable CM-representation type

FO Schreyer - Singularities, Representation of Algebras, and Vector …, 2006 - Springer
I include a complete proof of this result in this survey article. My emphasis lies on the
conscruction of maximal Cohen-Macaulay modules via matrix factorizations (section 2), from …

On local rings without small Cohen-Macaulay algebras in mixed characteristic

K Shimomoto, E Tavanfar - arXiv preprint arXiv:2109.12700, 2021 - arxiv.org
For any $ d\ge 4$, by deformation theory of schemes, we present examples of (complete or
excellent) $ d $-dimensional mixed characteristic normal local domains admitting no small …

Skew graded hypersurface singularities

K Ueyama - Comptes Rendus. Mathématique, 2023 - comptes-rendus.academie-sciences …
For a skew version of a graded (A∞) hypersurface singularity A, we study the stable
category of graded maximal Cohen-Macaulay modules over A. As a consequence, we see …

Semicontinuity for representations of one-dimensional Cohen-Macaulay rings

YA Drozd, GM Greuel - arXiv preprint alg-geom/9602015, 1996 - arxiv.org
We show that the number of parameters for CM-modules of prescribed rank is semi-
continuous in families of CM rings of Krull dimension 1. This transfers a result of Knoerrer …

[PDF][PDF] On the associated graded modules of canonical modules

A Ooishi - Journal of Algebra, 1991 - core.ac.uk
The canonical modules of Cohen-Macaulay rings give a useful technical tool in commutative
algebra, algebraic geometry, and singularity theory via various duality theorems. But not …