Not signed in (Sign In)

Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

  • Sign in using OpenID

Site Tag Cloud

2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry book bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics complex complex-geometry computable-mathematics computer-science constructive cosmology deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration foundation foundations functional-analysis functor gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory integration integration-theory internal-categories k-theory lie-theory limits linear linear-algebra locale localization logic mathematics measure measure-theory modal modal-logic model model-category-theory monad monads monoidal monoidal-category-theory morphism motives motivic-cohomology nlab noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pages pasting philosophy physics pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf simplicial space spin-geometry stable-homotopy-theory stack string string-theory superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory tqft type type-theory universal variational-calculus

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to nForum
If you want to take part in these discussions either sign in now (if you have an account), apply for one now (if you don't).
    • CommentRowNumber1.
    • CommentAuthorColin Zwanziger
    • CommentTimeSep 16th 2014
    • (edited Sep 16th 2014)

    Is there a reason we don’t care about these?

    We could have something like: k-tuply posetal n-categories are the same as k-1-tuply posetal n+1 categories (with distinguished n+1-morphisms in each inhabited hom-set between n-morphisms) with parallel n+1-morphisms equivalent

    • CommentRowNumber2.
    • CommentAuthorColin Zwanziger
    • CommentTimeSep 16th 2014
    • (edited Sep 16th 2014)

    I suppose it has something to do with the fact that this stabilizes for k>1!

    • CommentRowNumber3.
    • CommentAuthorColin Zwanziger
    • CommentTimeSep 16th 2014
    • (edited Sep 16th 2014)

    So these are just n-posets I guess. The reason I asked the question is we do appear to have the right kind of adjoint pair between Posets (“1-tuply posetal 0-cats”) and Categories with a distinguished morphism in each inhabited hom set [distinguished morphisms closed under composition and include identities] (“0-tuply posetal 1 cats”) that restricts to the equivalence of posets and posets-viewed-as-categories.

    • CommentRowNumber4.
    • CommentAuthorTobyBartels
    • CommentTimeSep 16th 2014

    Higher posets are more fundamental than higher categories. It's backwards to think of posetal categories as a modification of categories. Rather, an nn-category is a 11-tuply groupoidal (n+1)(n+1)-poset (and an nn-groupoid is an (n+1)(n+1)-tuply groupoidal (n+1)(n+1)-poset).

    But the usual numbering scheme goes the other way: an nn-groupoid is an (n,0)(n,0)-category, an nn-category is an (n,n)(n,n)-category, and an (n+1)(n+1)-poset is an (n,n+1)(n,n+1)-category. It's sheer bigotry that we use ‘category’ as the base of this naming scheme (rather than the extreme concepts of groupoid and poset), and then use an unnatural numbering scheme (from 00 to n+1n+1) to match that.