English

Pentagrams and paradoxes

Quantum Physics 2022-03-16 v1

Abstract

Klyachko and coworkers consider an orthogonality graph in the form of a pentagram, and in this way derive a Kochen-Specker inequality for spin 1 systems. In some low-dimensional situations Hilbert spaces are naturally organised, by a magical choice of basis, into SO(N) orbits. Combining these ideas some very elegant results emerge. We give a careful discussion of the pentagram operator, and then show how the pentagram underlies a number of other quantum "paradoxes", such as that of Hardy.

Keywords

Cite

@article{arxiv.0909.4713,
  title  = {Pentagrams and paradoxes},
  author = {Piotr Badziag and Ingemar Bengtsson and Adan Cabello and Helena Granstrom and Jan-Åke Larsson},
  journal= {arXiv preprint arXiv:0909.4713},
  year   = {2022}
}

Comments

14 pages, 4 figures

R2 v1 2026-06-21T13:50:37.101Z