Linear preservers of semi-positive matrices
Jonathan Dorsey, Tom Gannon, Nathaniel P. Jacobson, Charles R. Johnson, Morrison Turnansky · Linear and Multilinear Algebra · 2015
Considered are linear maps on m-by-n matrices that preserve the semi-positive matrices. The onto preservers are characterized, as well as the into preservers of the special form . Examples are given of into preservers that are not XAY maps, and a conjecture is made about the invertible, into preservers.