English

Commuting Magic Square Matrices

General Mathematics 2020-09-09 v1

Abstract

We review a known method of compounding two magic square matrices of order m and n with the all-ones matrix to form two magic square matrices of order mn. We show that these compounded matrices commute. Simple formulas are derived for their Jordan form and singular value decomposition. We verify that regular (associative) and pandiagonal commuting magic squares can be constructed by compounding. In a special case the compounded matrices are similar. Generalization of compounding to a wider class of commuting magic squares is considered. Three numerical examples illustrate our theoretical results.

Keywords

Cite

@article{arxiv.2009.03499,
  title  = {Commuting Magic Square Matrices},
  author = {Ronald P. Nordgren},
  journal= {arXiv preprint arXiv:2009.03499},
  year   = {2020}
}

Comments

18 pages, 3 examples. 2 commuting order-25 ultra magic square matrices in Ancillary File