English

On the Fundamental Group of Type II$_1$ Factors

Operator Algebras 2007-05-23 v1 Group Theory

Abstract

We present here a shorter version of the proof of a result from our paper ``On a class of type II1_1 factors with Betti numbers invariants'', showing that the von Neumann factor associated with the group Z2SL(2,Z)\Bbb Z^2 \rtimes SL(2, \Bbb Z) has trivial fundamental group.

Cite

@article{arxiv.math/0210467,
  title  = {On the Fundamental Group of Type II$_1$ Factors},
  author = {Sorin Popa},
  journal= {arXiv preprint arXiv:math/0210467},
  year   = {2007}
}