References Page 1 References [1] S. Abhyankar, S. Wiegand, On the compositum of two power
series rings, Proc. Amer. Math. Soc. 112 (1991), 629 – 636. [2] U. Albrecht, Endomorphism …

We introduce a general version of the singular compactness theorem which makes it
possible to show that being a Σ Σ-cotorsion module is a property of the complete theory of …

Drinfeld recently suggested to replace projective modules by the flat Mittag-Leffler ones in
the definition of an infinite dimensional vector bundle on a scheme X (Drinfeld, 2006 [8]) …

Mittag-Leffler modules occur naturally in algebra, algebraic geometry, and model
theory,[20],[14],[19]. If R is a non-right perfect ring, then it is known that in contrast with the …

A classic result by Bass says that the class of all projective modules is covering if and only if
it is closed under direct limits. Enochs extended the if-part by showing that every class of …

In this paper, we introduce and study the class S-ℱ-ML of S-Mittag-Leffler modules with
respect to all flat modules. We show that a ring R is S-coherent if and only if every ideal is in …

Homological tilting modules of finite projective dimension are investigated. They generalize
both classical and good tilting modules of projective dimension at most one, and produce …

Kaplansky classes emerged in the context of Enochs' solution of the Flat Cover Conjecture.
Their connection to abstract model theory goes back to Baldwin et al.: a class of roots of Ext …

A basic question for any property of quasi–coherent sheaves on a scheme $ X $ is whether
the property is local, that is, it can be defined using any open affine covering of $ X …

A classic result by Raynaud and Gruson says that the notion of an (infinite-dimensional)
vector bundle is Zariski local. This result may be viewed as a particular instance (for n= 0) of …