Homotopy theory of stricter $n$-categories
Clémence Chanavat
TL;DR
The paper introduces stricter $oldsymbol{ ext{n}}$-categories by enforcing higher exchange laws via Hadzihasanovic's regular directed complexes, and develops foundational tools such as the Gray product and suspension. It constructs a folk model structure on stricter $oldsymbol{ ext{n}}$-categories and demonstrates that this structure is right transferred from the diagrammatic $(orall\,n)$-model structure through a diagrammatic nerve, connecting strict models to diagrammatic set models of $(orall\,n)$-categories. A key result is that the walking equivalence in stricter $oldsymbol{ ext{ω}}$-categories aligns with the stricter polygraph generated by walking equivalences in diagrammatic sets, illuminating how these two formalisms mirror each other in the appropriate dimension range. The work lays groundwork for comparing the diagrammatic and standard models of $(orall\,n)$-categories (notably for $n\, ext{≤}\,3$) and establishes a coherent homotopy-theoretic framework for stricter higher categories, with a strong emphasis on functoriality, monoidality, and transfer of model structures.
Abstract
We make strict $n$-categories even stricter by requiring they satisfy higher exchange laws governed by Hadzihasanovic's theory of regular directed complexes. We study the first properties of stricter $n$-categories, in particular, we define the Gray product, and prove stability under suspension, which is non-trivial. After reviewing and briefly expanding the theory diagrammatic sets and their associated model structures for $(\infty, n)$-categories, we construct a folk model structure on stricter $n$-categories, show that the walking equivalence coincides with the stricter polygraph generated by the walking equivalence in diagrammatic sets, and finally, that the folk model structure on stricter $n$-categories is right transferred from the diagrammatic model structure along a nerve construction.
