English

A tale of three diagonalizations

High Energy Physics - Phenomenology 2021-02-26 v3 Quantum Physics

Abstract

In addition to the diagonalization of a normal matrix by a unitary similarity transformation, there are two other types of diagonalization procedures that sometimes arise in quantum theory applications -- the singular value decomposition and the Autonne-Takagi factorization. In these pedagogical notes, we carry out each of these diagonalization procedures for the most general 2×22\times 2 matrices for which the corresponding diagonalization is possible and provide explicit analytical results in each of the three cases.

Keywords

Cite

@article{arxiv.2009.03990,
  title  = {A tale of three diagonalizations},
  author = {Howard E. Haber},
  journal= {arXiv preprint arXiv:2009.03990},
  year   = {2021}
}

Comments

27 pages; version 2 adds a footnote 14 and improves the pdf output by modifying the implementation of hyperref; version 3 corrects an error in eq. (78)

R2 v1 2026-06-23T18:24:10.600Z