A complete classification of additive rank–one nonincreasing maps on hermitian matrices over Galois field GF (22) is obtained. This field is special and was not covered in a previous paper. As a consequence, some known applications, like the classification of additive rank–additivity preserving maps, are extended to arbitrary fields. An application concerning the preservers of hermitian varieti...

We prove that Jordan triple elementary surjective maps on unital rings containing a nontrivial idempotent are automatically additive. The first result about the additivity of maps on rings was given by Martindale III in an excellent paper [7]. He established a condition on a ring R such that every multiplicative bijective map on R is additive. More precisely, he proved the following theorem. Th...

Let $mathcal {A} $ and $mathcal {B} $ be C$^*$-algebras. Assume that $mathcal {A}$ is of real rank zero and unital with unit $I$ and $k>0$ is a real number. It is shown that if $Phi:mathcal{A} tomathcal{B}$ is an additive map preserving $|cdot|^k$ for all normal elements; that is, $Phi(|A|^k)=|Phi(A)|^k $ for all normal elements $Ainmathcal A$, $Phi(I)$ is a projection, and there exists a posit...

We prove that Jordan elementary surjective maps on rings are automatically additive. Elementary operators were originally introduced by Brešar and Šerml ([1]). In the last decade, elementary maps on operator algebras as well as on rings attracted more and more attentions. It is very interesting that elementary maps and Jordan elementary maps on some algebras and rings are automatically additive...

In this paper, we characterize a class of additive maps on Hilbert C∗-modules which maps a ”rank one” adjointable operators to another rank one operators.