Algebra Commons^™

Balance In Generalized Tate Cohomology, Alina Iacob

Alina Iacob

We consider two preenveloping classes of left R-modules ℐ, ℰ such that Inj ⊂ ℐ ⊂ ℰ, and a left R-module N. For any left R-module M and n ≥ 1 we define the relative extension modules (M, N) and prove the existence of an exact sequence connecting these modules and the modules (M, N) and (M, N). We show that there is a long exact sequence of (M, −) associated with a Hom(−, ℰ) exact sequence 0 → N′ → N → N′′ → 0 and a long exact sequence of (−, N) associated with a Hom(−, ℰ) exact …