Unital Kadison-Schwarz Maps
Quantum Physics
2025-09-23 v1 Mathematical Physics
math.MP
Abstract
Quantum entanglement is an important phenomenon in quantum information theory. To detect entanglement theoretically, positive but not completely positive maps are used. The Kadison-Schwarz (KS) inequality interpolates between positivity and complete positivity. KS maps may be key to understanding and detecting entanglement. We provide a description of a subset of KS maps on that are unital. This allows for the classification of a wider class of positive maps than the well known bistochastic maps. We derive the conditions for a unital map to be a KS map, and provide non-trivial examples of such a map.
Cite
@article{arxiv.2509.16368,
title = {Unital Kadison-Schwarz Maps},
author = {Hajir Al Zadjali and Farrukh Mukhamedov},
journal= {arXiv preprint arXiv:2509.16368},
year = {2025}
}