English

Decomposition of Borel graphs and cohomology

Group Theory 2026-03-12 v3 Dynamical Systems Logic

Abstract

We give a cohomological criterion for certain decomposition of Borel graphs, which is an analog of Dunwoody's work on accessibility of groups. As an application, we prove that a Borel graph (X,G)(X,G) with uniformly bounded degrees of cohomological dimension one is Lipschitz equivalent to a Borel acyclic graph on XX. This gives a new proof of a result of Chen-Poulin-Tao-Tserunyan on Borel graphs with components quasi-isometric to trees.

Keywords

Cite

@article{arxiv.2504.17831,
  title  = {Decomposition of Borel graphs and cohomology},
  author = {Hiroki Ishikura},
  journal= {arXiv preprint arXiv:2504.17831},
  year   = {2026}
}

Comments

Introduction is updated