English

The circular Delannoy category

Representation Theory 2023-03-21 v1

Abstract

Let GG (resp. HH) be the group of orientation preserving self-homeomorphisms of the unit circle (resp. real line). In previous work, the first two authors constructed pre-Tannakian categories Rep(G)\underline{\mathrm{Rep}}(G) and Rep(H)\underline{\mathrm{Rep}}(H) associated to these groups. In the predecessor to this paper, we analyzed the category Rep(H)\underline{\mathrm{Rep}}(H) (which we named the ``Delannoy category'') in great detail, and found it to have many special properties. In this paper, we study Rep(G)\underline{\mathrm{Rep}}(G). The primary difference between these two categories is that Rep(H)\underline{\mathrm{Rep}}(H) is semi-simple, while Rep(G)\underline{\mathrm{Rep}}(G) is not; this introduces new complications in the present case. We find that Rep(G)\underline{\mathrm{Rep}}(G) is closely related to the combinatorics of objects we call Delannoy loops, which seem to have not previously been studied.

Cite

@article{arxiv.2303.10814,
  title  = {The circular Delannoy category},
  author = {Nate Harman and Andrew Snowden and Noah Snyder},
  journal= {arXiv preprint arXiv:2303.10814},
  year   = {2023}
}

Comments

38 pages

R2 v1 2026-06-28T09:23:19.148Z