English

The equivariant model structure on cartesian cubical sets

Algebraic Topology 2026-04-21 v3 Logic in Computer Science Logic

Abstract

We develop a constructive model of homotopy type theory in a Quillen model category that classically presents the usual homotopy theory of spaces. Our model is based on presheaves over the cartesian cube category, a well-behaved Eilenberg-Zilber category. The key innovation is an additional equivariance condition in the specification of the cubical Kan fibrations, which can be described as the pullback of an interval-based class of uniform fibrations in the category of symmetric sequences of cubical sets. The main technical results in the development of our model have been formalized in a computer proof assistant.

Keywords

Cite

@article{arxiv.2406.18497,
  title  = {The equivariant model structure on cartesian cubical sets},
  author = {Steve Awodey and Evan Cavallo and Thierry Coquand and Emily Riehl and Christian Sattler},
  journal= {arXiv preprint arXiv:2406.18497},
  year   = {2026}
}

Comments

v2: Corrected a mistake in the treatment of notions of fibred structure. Some numbering has changed in sections 2.1 and 2.3. v3: Final journal version

R2 v1 2026-06-28T17:20:11.427Z