In this paper, we focus on the relationship between upper generalized semi-Fredholm and
weakly demicompact operators acting on Banach spaces and we use this relation to extend …

In this paper, we investigate the concept of generalized weakly demicompact operators with
respect to weakly closed densely defined linear operators. We give their relationship with …

In this paper, we show that an unbounded weakly S0-demicompact linear operator T,
introduced in [18], acting on a Banach space, can be characterized by some measures of …

In this paper, we investigate the concept of demicompactness and we establish some new
results in Fredholm theory connected with the existence of selections of a given linear …

In this paper, we introduce the concept of generalized weakly S-demicompact operators with
respect to a weakly closed linear operator S. We study the general setting of Fredholm …

In this paper, we introduce and investigate a new concept that we call demicompact
elements in Banach algebras as a generalization of demicompact linear operators acting on …

The paper is devoted to some new sufficient conditions to ensure the upper-Fredholmness
and Fredholmness of an unbounded densely defined linear operator T acting on a Banach …

In this paper, our central focus is upon a class of linear operators acting on a Banach space
X called relatively pseudo weakly demicompact operators. We clarify and determine the …

In this paper, we investigate the S 0 n-demicompactness of the restriction T n of a bounded
or unbounded linear operator T to R (T n), where S 0 n is the restriction of a given bounded …

In this paper, we establish some properties for a uniformly continuous cosine family (C (t))
t∈ R which has the property that C (t) is demicompact for some (resp. every) t> 0. More …