English

Computing Euler characteristics using quantum field theory

Group Theory 2025-04-23 v2 High Energy Physics - Theory Mathematical Physics Combinatorics math.MP

Abstract

This paper explains how to use quantum field theory techniques to find formal power series that encode the virtual Euler characteristics of Out(Fn)\mathrm{Out}(F_n) and related graph complexes. Finding such power series was a necessary step in the asymptotic analysis of χ(Out(Fn))\chi(\mathrm{Out}(F_n)) carried out in the authors' previous paper.

Keywords

Cite

@article{arxiv.2202.08739,
  title  = {Computing Euler characteristics using quantum field theory},
  author = {Michael Borinsky and Karen Vogtmann},
  journal= {arXiv preprint arXiv:2202.08739},
  year   = {2025}
}

Comments

13 pages, many figures; v2: final accepted manuscript with corrected typos

R2 v1 2026-06-24T09:42:55.992Z