Let H be an infinite-dimensional separable complex Hilbert space and B(H) the algebra of all bounded linear operators on H. In this paper, we characterized maps ϕ:B(H)→B(H), which are surjective up to compact preserving set left semi-Weyl in both directions. As application, proved that ϕ preserves essential approximate point spectrum if only ideal is invariant under induced map φ Calkin automor...

In this article we studied Nielsen coincidence theory for maps between manifolds of same dimension without hypotheses on orientation. We use the definition of semi-index of a class, we review the definition of defective classes and study the appearance of defective root classes. We proof a semi-index product formula type for lifting maps and we presented conditions such that defective coinciden...