Nonsymmetric normal entry patterns with the maximum number of distinct indeterminates

Authors：Huang Zejun; Zhan Xingzhi^*

Source：Linear Algebra and Its Applications, 2015, 485.

DOI：10.1016/j.laa.2015.08.003

• 0-1 matrices
• Entry pattern
• Nonsymmetric
• Normal matrices

Abstract We prove that a nonsymmetric normal entry pattern of order n (n≥3) has at most n(n-3)/2+3 distinct indeterminates and up to permutation similarity this number is attained by a unique pattern which is explicitly described. An open problem is posed.