English

Combinatorial skeletons of 2-cobordism and annular categories with applications to equational logic

Category Theory 2026-03-18 v2 Group Theory Geometric Topology

Abstract

We introduce a complete set of combinatorial data that encode the category 2Cob2\mathfrak{Cob} of all 22-cobordisms. As an application, we show that the local monoids of 2Cob2\mathfrak{Cob} do not have finitely axiomatizable equational theories. As yet another application, we construct a von-Neumann-regular extension of this category. Similar results are provided for the topological annular category and various quotients of the latter, like the affine Temperley--Lieb category.

Keywords

Cite

@article{arxiv.2002.01016,
  title  = {Combinatorial skeletons of 2-cobordism and annular categories with applications to equational logic},
  author = {Karl Auinger and Mikhail Volkov},
  journal= {arXiv preprint arXiv:2002.01016},
  year   = {2026}
}

Comments

Version 2 is radically reworked and substantially extended and should therefore be considered essentially a new paper. 95 pages, 13 numbered figures and many unnumbered illustrations, 1 table