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Artículo
Structure of the fixed point set and common fixed points of asymptotically nonexpansive mappings
(American Mathematical Society, 2001)
Let X be a Banach space, C a weakly compact convex subset of X and T : C → C an asymptotically nonexpansive mapping. Under the usual assumptions on X which assure the existence of fixed point for T, we prove that the set ...
Artículo
Norms of hypercyclic sequences
(The European Digital Mathematics Library, 2004)
In this note, is proved that every member of a wide class of Banach spaces supports a sequence (Tn) of operators with a hereditary hypercyclic subsequence (Tnk) such that (Tn) itself does not satisfy the so-called ...
Artículo
The fixed point property and unbounded sets in CAT(0) spaces
(Elsevier, 2013-12-15)
In this work we study the fixed point property for nonexpansive self-mappings defined on convex and closed subsets of a CAT(0) space. We will show that a positive answer to this problem is very much linked with the Euclidean ...
Artículo
Hardy-Littlewood inequalities for norms of positive operators on sequence spaces
(Elsevier, 2013-01-01)
We consider estimates of Hardy and Littlewood for norms of operators on sequence spaces, and we apply a factorization result of Maurey to obtain improved estimates and simplified proofs for the special case of a positive operator.
Artículo
Some examples of matrix-valued orthogonal functions having a differential and an integral operator as eigenfunctions
(Elsevier, 2011-05)
The aim of this paper is to show some examples of matrix-valued orthogonal functions on the real line which are simultaneously eigenfunctions of a second-order differential operator of Schrödinger type and an integral ...
Artículo
Universal matrix transforms of holomorphic functions
(University of Houston, 2006)
The phenomenon of overconvergence is related with the convergence of subsequences of the sequence of partial sums of Taylor series at points outside their disk of convergence. During the seventies Chui and Parnes and the ...
Artículo
A fixed point theorem for weakly Zamfirescu mappings
(Elsevier, 2011-03-01)
In [13] T. Zamfirescu, Fixed point theorems in metric spaces, Arch. Math. 23 (1972), 292–298. Zamfirescu gave a fixed point theorem that generalizes the classical fixed point theorems by Banach, Kannan and Chatterjea. In ...
Artículo
Vector spaces of non-extendable holomorphic functions
(Springer, 2018-02)
In this paper, the linear structure of the family He(G) of holomorphic functions in a domain G of the complex plane that are not analytically continuable beyond the boundary of G is analyzed. We prove that He(G) contains, ...
Artículo
On selections of the metric projection and best proximity pairs in hyperconvex spaces
(Maria Curie-Skłodowska University, 2005)
In this work we present new results on nonexpansive retractions and best proximity pairs in hyperconvex metric spaces. We sharpen the main results of R. Esp´ınola et al. in [3] (Nonexpansive retracts in hyperconvex spaces, ...
Artículo
On a unified study of relative Chebyshev radii and Hausdorff measures of noncompactness
(University of Houston, 2004)
The paper is concerned with the notion of the Lifschitz modulus and its relationship with both relative Chebyshev radii and Hausdorff measures of noncompactness.