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The Importance of Being Unistochastic

Quantum Physics 2007-05-23 v1

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.

Cite

@article{arxiv.quant-ph/0403088,
  title  = {The Importance of Being Unistochastic},
  author = {Ingemar Bengtsson},
  journal= {arXiv preprint arXiv:quant-ph/0403088},
  year   = {2007}
}

Comments

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

R2 v1 2026-07-22T19:43:12.731Z