model category, model $\infty$-category
Definitions
Morphisms
Universal constructions
Refinements
Producing new model structures
Presentation of $(\infty,1)$-categories
Model structures
for $\infty$-groupoids
on chain complexes/model structure on cosimplicial abelian groups
related by the Dold-Kan correspondence
for equivariant $\infty$-groupoids
for rational $\infty$-groupoids
for rational equivariant $\infty$-groupoids
for $n$-groupoids
for $\infty$-groups
for $\infty$-algebras
general $\infty$-algebras
specific $\infty$-algebras
for stable/spectrum objects
for $(\infty,1)$-categories
for stable $(\infty,1)$-categories
for $(\infty,1)$-operads
for $(n,r)$-categories
for $(\infty,1)$-sheaves / $\infty$-stacks
The notion of a premodel category is a relaxation of the notion of a model category. Combinatorial premodel categories form a 2-category that has all (small) limits and colimits and has representing objects for Quillen bifunctors.
The 2-category of combinatorial $V$-enriched premodel categories is the category of modules over a monoid $V$ in this 2-category. It inherits the same set of properties and additionally admits a model 2-category structure. In this model structure, a left Quillen functor is a weak equivalence if and only if it is a Quillen equivalence.
A premodel category is a bicomplete category equipped with a pair of weak factorization systems $(C,AF)$ and $(AC,F)$ such that $AC\subset C$ (equivalently, $AF\subset F$).
Model categories can be singled out among premodel categories by imposing the additional requirement that the class
obtained by composing elements of $AC$ with those of $AF$, is closed under the 2-out-of-3 property.
The members of AC are called anodyne cofibrations and the members of AF are called anodyne fibrations (as in anodyne morphism).
The notion of premodel category doesn’t come with a good general notion of weak equivalence. But if a particular premodel category has a good notion of weak equivalence, such as one of Barton‘s relaxed premodel categories, one needs to distinguish between two types of cofibrations (and analogously between two types of fibrations):
In principle one must also distinguish a third class of cofibrations that have the left lifting property with respect to fibrations between fibrant objects. However, in a relaxed premodel category, these are trivial cofibrations. (Barton, Prop 3.5.2)
Last revised on May 9, 2020 at 18:38:11. See the history of this page for a list of all contributions to it.