English

Random length-spectrum rigidity for free groups

Group Theory 2011-02-07 v3 Geometric Topology

Abstract

We say that a subset SFNS\subseteq F_N is \emph{spectrally rigid} if whenever T1,T2cvNT_1, T_2\in cv_N are points of the (unprojectivized) Outer space such that gT1=gT2||g||_{T_1}=||g||_{T_2} for every gSg\in S then T1=T2T_1=T_2 in \cvn\cvn. It is well-known that FNF_N itself is spectrally rigid; it also follows from the result of Smillie and Vogtmann that there does not exist a finite spectrally rigid subset of FNF_N. We prove that if AA is a free basis of FNF_N (where N2N\ge 2) then almost every trajectory of a non-backtracking simple random walk on FNF_N with respect to AA is a spectrally rigid subset of FNF_N.

Keywords

Cite

@article{arxiv.1001.1729,
  title  = {Random length-spectrum rigidity for free groups},
  author = {Ilya Kapovich},
  journal= {arXiv preprint arXiv:1001.1729},
  year   = {2011}
}

Comments

12 pages, no figures; to appear in Proceedings of the American Mathematical Society; updated ref to the Duchin-Leininger-Rafi paper

R2 v1 2026-06-21T14:33:17.697Z