Etudiant : OUAHABI SOUFYANE

Filière : Master Mathématiques Pures (MMP)

Encadrant : Pr. BENBOUZIANE HASSANE

Annèe : 2024

Résumé : Preserving problems in operator theory in recent decades are a topic of interest to many mathematicians. In these problems, the authors are interested in describing mappings defined on operator algebras which leaves some functions, subsets, relations, etc. fixed. We have seen through this project two types of maps preserving the ascent and the descent of operators: the first one is additive in the case of Hilbert space and the second one preserves the ascent and the descent of product of operators in general for a Banach space.