Dominant local rings and subcategory classification

R Takahashi - International Mathematics Research Notices, 2023 - academic.oup.com
We introduce a new notion of commutative noetherian local rings, which we call dominant.
We explore fundamental properties of dominant local rings and compare them with other …

Local rings with quasi-decomposable maximal ideal

S Nasseh, R Takahashi - Mathematical Proceedings of the …, 2020 - cambridge.org
Let (R, 𝔪) be a commutative noetherian local ring. In this paper, we prove that if 𝔪 is
decomposable, then for any finitely generated R-module M of infinite projective dimension 𝔪 …

Vanishing of Ext and Tor over fiber products

S Nasseh, S Sather-Wagstaff - Proceedings of the American Mathematical …, 2017 - ams.org
Consider a non-trivial fiber product $ R= S\times _kT $ of local rings $ S $, $ T $ with
common residue field $ k $. Given two finitely generated $ R $-modules $ M $ and $ N $, we …

[HTML][HTML] Applications and homological properties of local rings with decomposable maximal ideals

S Nasseh, S Sather-Wagstaff, R Takahashi… - Journal of Pure and …, 2019 - Elsevier
We construct a local Cohen–Macaulay ring R with a prime ideal p∈ Spec (R) such that R
satisfies the uniform Auslander condition (UAC), but the localization R p does not satisfy …

Complexity and rigidity of Ulrich modules, and some applications

S Dey, D Ghosh - arXiv preprint arXiv:2201.00984, 2022 - arxiv.org
We analyze whether Ulrich modules, not necessarily maximal CM (Cohen-Macaulay), can
be used as test modules, which detect finite homological dimensions of modules. We prove …

Homology over trivial extensions of commutative DG algebras

LL Avramov, SB Iyengar, S Nasseh… - Communications in …, 2019 - Taylor & Francis
Conditions on the Koszul complex of a noetherian local ring R guarantee that Tor i R (M, N)
is nonzero for infinitely many i, when M and N are finitely generated R-modules of infinite …

Naïve liftings of DG modules

S Nasseh, M Ono, Y Yoshino - Mathematische Zeitschrift, 2022 - Springer
Let n be a positive integer, and let A be a strongly commutative differential graded (DG)
algebra over a commutative ring R. Assume that B= A [X 1,…, X n] is a polynomial extension …

Diagonal tensor algebra and naive liftings

S Nasseh, M Ono, Y Yoshino - arXiv preprint arXiv:2309.05293, 2023 - arxiv.org
The notion of naive lifting of DG modules was introduced by the authors in [16, 17] for the
purpose of studying problems in homological commutative algebra that involve self …

[HTML][HTML] Burch index, summands of syzygies and linearity in resolutions

H Dao, D Eisenbud - Bulletin of the Iranian Mathematical Society, 2023 - Springer
The Burch index is a new invariant of a local ring R whose positivity implies a kind of
linearity in resolutions of R-modules. We show that if R has depth zero and Burch index at …

Ring homomorphisms and local rings with quasi-decomposable maximal ideal

S Nasseh, KA Sather-Wagstaff… - Communications in …, 2024 - Taylor & Francis
The notion of local rings with quasi-decomposable maximal ideal was formally introduced by
Nasseh and Takahashi. In separate works, the authors of the present paper showed that …