Buscar
Mostrando ítems 1-6 de 6
Artículo
Mutually nearest and farthest points of sets and the Drop Theorem in geodesic spaces
(Springer, 2012-02)
Let A and X be nonempty, bounded and closed subsets of a geodesic metric space (E, d). The minimization (resp. maximization) problem denoted by min(A, X) (resp. max(A, X)) consists in finding (a0,x0)∈A×X(a0,x0)∈A×X such ...
Artículo
Geodesic Ptolemy spaces and fixed points
(Elsevier, 2011-01-01)
We prove that geodesic Ptolemy spaces with a continuous midpoint map are strictly convex. Moreover, we show that geodesic Ptolemy spaces with a uniformly continuous midpoint map are reflexive and that in such a setting ...
Artículo
A proof-theoretic bound extraction theorem for CAT(κ)-spaces
(Springer, 2017-06)
Starting in 2005, general logical metatheorems have been developed that guarantee the extractability of uniform effective bounds from large classes of proofs of theorems that involve abstract metric structures X. In this ...
Artículo
Fixed points, selections and common fixed points for nonexpansive-type mappings
(Elsevier, 2011-10-15)
We study the existence of fixed points in the context of uniformly convex geodesic metric spaces, hyperconvex spaces and Banach spaces for single and multivalued mappings satisfying conditions that generalize the concept ...
Artículo
Quantitative asymptotic regularity results for the composition of two mappings
(Taylor & Francis, 2016)
In this paper, we use techniques which originate from proof mining to give rates of asymptotic regularity and metastability for a sequence associated to the composition of two firmly nonexpansive mappings.
Artículo
What do 'convexities' imply on Hadamard manifolds?
(Springer, 2016-09)
Various results based on some convexity assumptions (involving the exponential map along with affine maps, geodesics and convex hulls) have been recently established on Hadamard manifolds. In this paper we prove that these ...