A Remark on Projective Dimension of Fiat Modules.
Let A be a unital strict Banach algebra, and let K + be the one-point compactification of a discrete topological space K. Denote by the weak tensor product of the algebra A and C(K +), the algebra of continuous functions on K +. We prove that if K has sufficiently large cardinality (depending on A), then the strict global dimension is equal to .
We study the relations between finitistic dimensions and restricted injective dimensions. Let be a ring and a left -module with . If is selforthogonal, then we show that . Moreover, if is a left noetherian ring and is a finitely generated left -module with finite injective dimension, then . Also we show by an example that the restricted injective dimensions of a module may be strictly smaller than the Gorenstein injective dimension.
A certain class of Arens-Michael algebras having no non-zero injective topological ⨶-modules is introduced. This class is rather wide and contains, in particular, algebras of holomorphic functions on polydomains in , algebras of smooth functions on domains in , algebras of formal power series, and, more generally, any nuclear Fréchet-Arens-Michael algebra which has a free bimodule Koszul resolution.