The Importance of Being Unistochastic
Abstract
A bistochastic matrix is a square matrix with positive entries such that rows and columns sum to unity. A unistochastic matrix is a bistochastic matrix whose matrix elements are the absolute values squared of a unitary matrix. We can now ask questions such as when a given bistochastic matrix is unistochastic. I review these questions: Why they are asked, why they are difficult to answer, and what is known about them.
 Publication:

arXiv eprints
 Pub Date:
 March 2004
 arXiv:
 arXiv:quantph/0403088
 Bibcode:
 2004quant.ph..3088B
 Keywords:

 Quantum Physics
 EPrint:
 8 pages, contribution to the Second Vaxjo Conference of Quantum Theory: Reconsideration of Foundations