Nonnegativity for hafnians of certain matrices

Kamil Bradler, Shmuel Friedland, Robert Israel

We show that a complex symmetric matrix of the form $A(Y,B)=\left[\begin{array}{cc}Y& B\\ B^{\top }& \overline{Y}\end{array}\right],$ where $B$ is Hermitian positive semidefinite, has a nonne…