English

Examples of property (T) II$_1$ factors with trivial fundamental group

Operator Algebras 2020-03-31 v2 Group Theory

Abstract

In this article we provide the first examples of property (T) II1\rm II_1 factors N\mathcal N with trivial fundamental group, F(N)=1\mathcal F (\mathcal N)=1. Our examples arise as group factors N=L(G)\mathcal N=\mathcal L(G) where GG belong to two distinct families of property (T) groups previously studied in the literature: the groups introduced by Valette in \cite{Va04} and the ones introduced recently in \cite{CDK19} using the Belegradek-Osin Rips construction from \cite{BO06}. In particular, our results provide a continuum of explicit pairwise non-isomorphic property (T) factors.

Keywords

Cite

@article{arxiv.2003.08857,
  title  = {Examples of property (T) II$_1$ factors with trivial fundamental group},
  author = {Ionut Chifan and Sayan Das and Cyril Houdayer and Krishnendu Khan},
  journal= {arXiv preprint arXiv:2003.08857},
  year   = {2020}
}

Comments

New classes of property (T) factors with trivial fundamental groups added. New co-author added