We show that every injective homological ring epimorphism f:R--> S where S_R has flat dimension at most one gives rise to a 1-cotilting R-module and we give sufficient conditions under which the converse holds true. Specializing to the case of a valuation domain R, we illustrate a bijective correspondence between equivalence classes of injective homological ring epimorphisms originating in R and cotilting classes of certain type and in turn, a bijection with a class of smashing localizing subcategories of the derived category of R. Moreover, we obtain that every cotilting class over a valuation domain is a Tor-orthogonal class, hence it is of cocountable type even though in general cotilting classes are not of cofinite type.
Cotilting modules and homological ring epimorphisms
BAZZONI, SILVANA
2015
Abstract
We show that every injective homological ring epimorphism f:R--> S where S_R has flat dimension at most one gives rise to a 1-cotilting R-module and we give sufficient conditions under which the converse holds true. Specializing to the case of a valuation domain R, we illustrate a bijective correspondence between equivalence classes of injective homological ring epimorphisms originating in R and cotilting classes of certain type and in turn, a bijection with a class of smashing localizing subcategories of the derived category of R. Moreover, we obtain that every cotilting class over a valuation domain is a Tor-orthogonal class, hence it is of cocountable type even though in general cotilting classes are not of cofinite type.Pubblicazioni consigliate
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