English

Weighted cogrowth formula for free groups

Dynamical Systems 2018-02-26 v1 Probability

Abstract

We investigate the relationship between geometric, analytic and probabilistic indices for quotients of the Cayley graph of the free group Cay(Fn){\rm Cay}(F_n) endowed with variable edge lengths, by an arbitrary subgroup GG of FnF_n. Our main result, which generalizes Grigorchuk's cogrowth formula to variable edge lengths, provides a formula relating the bottom of the spectrum of weighted Laplacian on G\Cay(Fn)G \backslash {\rm Cay}(F_n) to the Poincar\'e exponent of GG. Our main tool is the Patterson-Sullivan theory for Cayley graphs with variable edge lengths.

Cite

@article{arxiv.1802.08361,
  title  = {Weighted cogrowth formula for free groups},
  author = {Johannes Jaerisch and Katsuhiko Matsuzaki},
  journal= {arXiv preprint arXiv:1802.08361},
  year   = {2018}
}
R2 v1 2026-06-23T00:30:56.531Z