A characterization of trace zero bisymmetric nonnegative $5\times 5$ matrices

Somchai Somphotphisut, Keng Wiboonton

Let ${\lambda }_1\ge {\lambda }_2\ge {\lambda }_3\ge {\lambda }_4\ge {\lambda }_5\ge -{\lambda }_1$ be real numbers such that ${\sum }_{i=1}^5{\lambda }_i=0$. In \cite{oren}, O. Spector prove that a necessary and sufficient condition…