On continuity of the Moore-Penrose and Drazin inverses.
Multipliers of mixed-norm sequence spaces and measures of noncompactness.
Quasicontraction nonself-mappings on convex metric spaces and common fixed point theorems.
Topological vector space-valued cone metric spaces and fixed point theorems.
Semi-Browder operators and perturbations
An operator in a Banach space is called upper (resp. lower) semi-Browder if it is upper (lower) semi-Fredholm and has a finite ascent (resp. descent). An operator in a Banach space is called semi-Browder if it is upper semi-Browder or lower semi-Browder. We prove the stability of the semi-Browder operators under commuting Riesz operator perturbations. As a corollary we get some results of Grabiner [6], Kaashoek and Lay [8], Lay [11], Rakočević [15] and Schechter [16].
On a formula for the jumps in the semi-Fredholm domain.
In this paper we prove some properties of the lower s-numbers and derive asymptotic formulae for the jumps in the semi-Fredholm domain of a bounded linear operator on a Banach space.
A note on regular elements in Calkin algebras.
An element a of the Banach algebra A is said to be regular provided there is an element b belonging to A such that a = aba. In this note we study the set of regular elements in the Calkin algebra C(X) over an infinite-dimensional complex Banach space X.
Measure of noncompactness of operators and matrices on the spaces and .
A Note on two Indices of Semigroup Elements
A note on a theorem of Vidav
Lower s-numbers and their asymptotic behaviour
Invertibility of the commutator of an element in a C*-algebra and its Moore-Penrose inverse
We study the subset in a unital C*-algebra composed of elements a such that is invertible, where denotes the Moore-Penrose inverse of a. A distinguished subset of this set is also investigated. Furthermore we study sequences of elements belonging to the aforementioned subsets.
Multipliers of Mixed-norm Sequence Spaces and Measures of Noncompactness, II
An IntroduCtion into the Theory of Sequence Spaces and Measures of Noncompactness
On the semi-Browder spectrum
An operator in a Banach space is called upper (lower) semi-Browder if it is upper (lower) semi-Fredholm and has a finite ascent (descent). We extend this notion to n-tuples of commuting operators and show that this notion defines a joint spectrum. Further we study relations between semi-Browder and (essentially) semiregular operators.
Fixed point result in controlled fuzzy metric spaces with application to dynamic market equilibrium
In this paper, we introduce -type controlled fuzzy metric spaces and establish some fixed point results in this spaces. We provide suitable examples to validate our result. We also employ an application to substantiate the utility of our established result for finding the unique solution of an integral equation emerging in the dynamic market equilibrium aspects to economics.
The sequence spaces defined by a modulus
Estimates for projections in Banach spaces and existence of direct complements
Let W and L be complementary subspaces of a Banach space X and let P(W,L) denote the projection on W along L. We obtain a sufficient condition for a subspace M of X to be complementary to W and we derive estimates for the norm of P(W,L) - P(W,M).
Page 1