The Universal Theory Of The Hyperfinite II Factor Is Not Computable
arXiv:2006.05629
Abstract
We show that the universal theory of the hyperfinite II factor is not computable. The proof uses the recent result that MIP*=RE. Combined with an earlier observation of the authors, this yields a proof that the Connes Embedding Problem has a negative solution that avoids the equivalences with Kirchberg's QWEP Conjecture and Tsirelson's Problem.+
Latest version contains a new result (Corollary 5.5) yielding infinitely many counterexamples to the Connes Embedding Problem