A ring is called n-Perfect (n≥ 0) if every flat module has projective dimension less or equal
than n. In this paper we introduce “Strong n-Perfect rings” which is in some way a …

The criterion for a ring to be left perfect and right coherent, found by SU Chase in 1960 [1], is
well-known. It requires that the direct product of an arbitrary (small) family of projective …

Let R be a ring. A left R-module M (respectively right R-module N) is called FI-injective
(respectively FI-flat) if Ext1 (G, M)= 0 (respectively Tor1 (N, G)= 0) for any FP-injective left R …

In this article, FP-injective complexes are introduced and studied. We prove that (⊥ ℱℐ, ℱℐ)
is a hereditary cotorsion theory if and only if R is a left coherent ring, where ℱℐ denotes the …

It is well known that the right global dimension of a ring R is usually computed by the right
derived functors of Hom and the left projective resolutions of right R-modules. In this paper …

Expanding Nakayama's original concept of dominant dimension, Tachikawa, Müller and
Kato have obtained a number of results pertaining to finite dimensional algebras and more …

Let R be a commutative ring. An R-module M is said to be an absolutely w-pure module if
Ext R 1 (F, M) is GV-torsion for any finitely presented R-module F. In this paper, we further …

Relatively Endocoherent Modules Page 1 Algebra Colloquium c© 2007 AMSS CAS & SUZHOU
UNIV Algebra Colloquium 14 : 2 (2007) 327–340 Relatively Endocoherent Modules∗ Lixin Mao …

In this paper we show that if R is a ring of Krull dimension d and M is a strongly copure flat
(respectively, strongly copure injective) module, then E⊗ RM (respectively, HomR (E, M)) is …