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7 votes
1 answer
359 views

How do the various homotopy 2-categories compare?

There are various models of $\infty$-categories floating around, so there are as many models of the associated homotopy 1- and 2-categories. Because the relations between the former are worked out in ...
Jonas Linssen's user avatar
6 votes
2 answers
944 views

Twisted-arrow construction for 2-categories

I've been looking over Lurie's DAG X, and he introduces a combinatorial construction called the twisted arrow construction for simplicial sets that generalizes the following ordinary categorical ...
Harry Gindi's user avatar
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5 votes
0 answers
120 views

Simplicial matrices and the nerves of weak n-categories II, III, and IV

Duskin introduced his nerve functor (see the nLab or Kerodon) in the paper Duskin, John W. Simplicial matrices and the nerves of weak n-categories I: nerves of bicategories. [Link]. While three ...
Emily's user avatar
  • 11.8k
4 votes
1 answer
545 views

What is the notion of a group object and its action in a 2-category?

It is well known that a group object in a category $C$ (with terminal object $1$ and such that any two objects of $C$ have a product) is defined as an object $G$ in $C$ with the following morphisms: $...
Adittya Chaudhuri's user avatar
3 votes
0 answers
81 views

A name in literature for a certain kind of 2-categories

Let $tr_2: \mathrm{sSet} \to \mathrm{sSet}_{\le 2} $ be the 2-truncation functor. Let $C$ be a 2-truncated simplicial set such that every horn $tr_2( \Lambda^2_1) \to C$ extends to $tr_2(\Delta_2) \...
Andrea Marino's user avatar
3 votes
0 answers
159 views

Recognition principle for 2-categories (2-groupoids)

Given a 2-category (i.e. bicategory) $C$ there is a unitary geometrical nerve whose 0-simplices are objects of $C$, 1-simplices are 1-arrows of $C$, 2-simplices are 2-commutative triangles (in certain ...
Ma Ming's user avatar
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