378 research outputs found
On the tensor product of linear sites and Grothendieck categories
We define a tensor product of linear sites, and a resulting tensor product of
Grothendieck categories based upon their representations as categories of
linear sheaves. We show that our tensor product is a special case of the tensor
product of locally presentable linear categories, and that the tensor product
of locally coherent Grothendieck categories is locally coherent if and only if
the Deligne tensor product of their abelian categories of finitely presented
objects exists. We describe the tensor product of non-commutative projective
schemes in terms of Z-algebras, and show that for projective schemes our tensor
product corresponds to the usual product scheme.Comment: New sections 5.3 on the alpha-Deligne tensor product and 5.4 on
future prospect
On exact categories and applications to triangulated adjoints and model structures
We show that Quillen's small object argument works for exact categories under
very mild conditions. This has immediate applications to cotorsion pairs and
their relation to the existence of certain triangulated adjoint functors and
model structures. In particular, the interplay of different exact structures on
the category of complexes of quasi-coherent sheaves leads to a streamlined and
generalized version of recent results obtained by Estrada, Gillespie, Guil
Asensio, Hovey, J{\o}rgensen, Neeman, Murfet, Prest, Trlifaj and possibly
others.Comment: 38 pages; version 2: major revision, more explanation added at
several places, reference list updated and extended, misprints correcte
A convenient category for directed homotopy
We propose a convenient category for directed homotopy consisting of
preordered topological spaces generated by cubes. Its main advantage is that,
like the category of topological spaces generated by simplices suggested by J.
H. Smith, it is locally presentable
Homotopy locally presentable enriched categories
We develop a homotopy theory of categories enriched in a monoidal model
category V. In particular, we deal with homotopy weighted limits and colimits,
and homotopy local presentability. The main result, which was known for
simplicially-enriched categories, links homotopy locally presentable
V-categories with combinatorial model V-categories, in the case where has all
objects of V are cofibrant.Comment: 48 pages. Significant changes in v2, especially in the last sectio
Locally class-presentable and class-accessible categories
We generalize the concepts of locally presentable and accessible categories.
Our framework includes such categories as small presheaves over large
categories and ind-categories. This generalization is intended for applications
in the abstract homotopy theory
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