On Hermitian-Invertors

Abstract

Specializing an invertor [20] to a linear transformation on $M_n$ for which the image of any hermitian matrix is skew-hermitian yields a hermitian-invertor. This paper gives twelve characterizations of hermitian-invertors and lists other basic results for them. It gives a set of unifying results in a reflector setting and concludes with some remarks on ${\mathbb Z}$-linear maps in the Djoković setting [7].