Some linear preserver problems onB(H) concerning rank and corank

Some Linear Preserver Problems on B(h) concerning Rank and Corank

As a continuation of the work on linear maps between operator algebras which preserve certain subsets of operators with finite rank, or finite corank, here we consider the problem inbetween, that is, we treat the question of preserving operators with infinite rank and infinite corank. Since, as it turns out, in this generality our preservers cannot be written in a nice form what we have got use...

Some General Techniques on Linear Preserver Problems

Several general techniques on linear preserver problems are described. The first one is based on a transfer principle in Model Theoretic Algebra that allows one to extend linear preserver results on complex matrices to matrices over other algebraically closed fields of characteristic 0. The second one concerns the use of some simple geometric technique to reduce linear preserver problems to sta...

Linear Preserver Problems

Linear preserver problems is an active research area in matrix and operator theory. These problems involve certain linear operators on spaces of matrices or operators. We give a general introduction to the subject in this article. In the first three sections, we discuss motivation, results, and problems. In the last three sections, we describe some techniques, outline a few proofs, and discuss ...

Some Ontological Problems concerning Predication

The Aristotelian double characterization of a primary substance exploits the difference between the part-whole relation and the non-linguistic relation of predication. A problem arises whether and how the second relation could be reduced to something else. Such a reduction is explicitly declared or at least implicitly assumed in all version of conceptualism and nominalism. The moderate realism ...

Some Unsolved Problems Concerning Bovine Tuberculosis