The almost-entropic regions are not semialgebraic
arXiv:1510.02658
Abstract
We prove that the almost-entropic region of order four is not semialgebraic, we get as a corollary the well-known Theorem of Matus, which asserts that this region is not polyhedral
9 pages The paper has been withdrawn by the authors due to a flaw in the proof of the main result