Open AccessOn strictly quasi-Fredholm linear relations and semi-B-Fredholm linear relation perturbations
Author(s) -
Maher Mnif,
Hafsa Bouaniza
Publication year - 2017
Publication title -
filomat
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.449
H-Index - 34
eISSN - 2406-0933
pISSN - 0354-5180
DOI - 10.2298/fil1720337b
Subject(s) - mathematics , fredholm theory , fredholm integral equation , descent (aeronautics) , fredholm determinant , rank (graph theory) , pure mathematics , perturbation (astronomy) , mathematical analysis , integral equation , combinatorics , aerospace engineering , engineering , physics , quantum mechanics
In this paper we introduce the set of strictly quasi-Fredholm linear relations and we give some of its properties. Furthermore, we study the connection between this set and some classes of linear relations related to the notions of ascent, essentially ascent, descent and essentially descent. The obtained results are used to study the stability of upper semi-B-Fredholm and lower semi-B-Fredholm linear relations under perturbation by finite rank operators.