A matrix A n n ∈C × is said to be secondary normal (s-normal)
if ΑΑθ = ΑθΑ .
Example 2.2:
The concept of s-normal matrices was introduced in [1]. Equivalent conditions on
normal matrices were given in [2]. In this paper, our intention is to define sunitarily
equivalent matrices and prove some equivalent conditions on s-normal
matrices. Also we prove some results on s-normal matrices. Let Cn ×n be the
space of n × n complex matrices.