Singular value structure of real matrices which can be expressed as a linear combination of two orthogonal matrices
Zheng Li, Tie Zhang, Changjun Li · Operators and Matrices · 2022
Can every real matrix be expressed as a linear combination of a certain number of orthogonal matrices? What is the smallest number of these orthogonal matrices? These elegant and interesting questions were initially raised by Zhan Soon afterwards, Li and Poon These classic results inspire us to further explore the improvement or supplement of this theory.