Browsing Artículos (Análisis Matemático) by Title
Now showing items 120 of 452

2º Congreso de Jóvenes Investigadores [Article]
(Real Sociedad Matematica Española, 2013) 
A Birkhoff theorem for Riemann surfaces [Article]
(Rocky Mountain Mathematics Consortium, 1998)A classical theorem of Birkhoff asserts that there exists an entire function f such that the sequence of function {/(z + n)}n≥o is dense in the space of entire functions. In this paper we give sufficient conditions on a ...

A Bp condition for the strong maximal function [Article]
(American Mathematical Society, 201411)A strong version of the Orlicz maximal operator is introduced and a natural Bp condition for the rectangle case is defined to characterize its boundedness. This fact let us to describe a sufficient condition for the two ...

A characterization of the classical orthogonal discrete and qpolynomials [Article]
(Elsevier, 20070401)In this paper we present a new characterization for the classical discrete and qclassical (discrete) polynomials (in the Hahn's sense).

A continuation method for weakly contractive mappings under the interior condition [Article]
(Hindawi, 2009)Recently, Frigon proved that, for weakly contractive maps, the property of having a fixed point is invariant by a certain class of homotopies, obtaining as a consequence a LeraySchauder alternative for this class of maps ...

A continuation method for weakly Kannan maps [Article]
(SpringerOpen, 2010)The first continuation method for contractive maps in the setting of a metric space was given by Granas. Later, Frigon extended Granas theorem to the class of weakly contractive maps, and recently Agarwal and O’Regan have ...

A criterion of weak compactness for operators on subspaces of Orlicz spaces [Article]
(Hindawi, 2008)We give a criterion of weak compactness for the operators on the MorseTransue space MΨ , the subspace of the Orlicz space LΨ generated by L∞.

A dynamical characterization of subArakelian subsets [Article]
(Elsevier, 20130915)We are going to characterize those sets which can be covered by an Arakelian set in terms of dynamical properties of entire functions via similarities. Moreover, if we consider the set of universal entire functions via ...

A fixed point theorem for weakly Zamfirescu mappings [Article]
(Elsevier, 20110301)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 ...

A Fredholm mapping of index zero [Article]
(Korean Mathematical Society, 2008)Sufficient conditions are given to assert that between any two Banach spaces over K Fredholm mappings share exactly N values in a specific open ball. The proof of the result is constructive and is based upon continuation methods.

A generalization of the classical Laguerre polynomials [Article]
(Springer, 1995)We consider a modi cation of the gamma distribution by adding a discrete measure supported in the point x = 0. For large n we analyze the existence of orthogonal polynomials with respect to such a distribution. Finally we ...

A geometrical coefficient implying the fixed point property and stability results [Article]
(University of Houston, 1996)In this paper we define a new geometric constant M(X) in Banach spaces such that X has the fixed point property for nonexpansive mappings if M(X) > 1. We prove that M(X) •_ WCS(X), the inequality being strict in many ...

A local spectral condition for strong compactness with some applications to bilateral weighted shifts [Article]
(American Mathematical Society, 201401)An algebra of bounded linear operators on a Banach space is said to be strongly compact if its unit ball is precompact in the strong operator topology, and a bounded linear operator on a Banach space is said to be strongly ...

A lot of “counterexamples” to Liouville's theorem [Article]
(Elsevier, 19960801)We prove in this paper that, given α ∈ (0, 1/2), there exists a linear manifold M of entire functions satisfying that M is dense in the space of all entire functions and, in addition, limz→∞ exp(zα) f(j)(z) = 0 on any ...

A lower bound for the equilateral number of normed spaces [Article]
(American Mathematical Society, 2008)We show that if the BanachMazur distance between an ndimensional normed space X and ℓ n∞ is at most 3/2, then there exist n + 1 equidistant points in X. By a wellknown result of Alon and Milman, this implies that an ...

A maximum principle for the Muskat problem for fluids with different densities [Article]
(Springer, 200903)We consider the fluid interface problem given by two incompressible fluids with different densities evolving by Darcy’s law. This scenario is known as the Muskat problem for fluids with the same viscosities, being in two ...

A new characterization of the Muckenhoupt Ap weights through an extension of the LorentzShimogaki theorem [Article]
(Indiana University, 2007)Given any quasiBanach function space X over Rn it is defined an index αX that coincides with the upper Boyd index αX when the space X is rearrangementinvariant. This new index is defined by means of the local maximal ...

A new quantitative two weight theorem for the HardyLittlewood maximal operator [Article]
(American Mathematical Society, 201502)A quantitative two weight theorem for the HardyLittlewood maximal operator is proved improving the known ones. As a consequence a new proof of the main results in [HP] and in [HPR12] is obtained which avoids the use of ...

A note on an ergodic theorem in weakly uniformly convex geodesic spaces [Article]
(Springer, 201511)Karlsson and Margulis [A. Karlsson, G. Margulis, A multiplicative ergodic theorem and nonpositively curved spaces. Commun. Math. Phys. 208 (1999), 107123] proved in the setting of uniformly convex geodesic spaces, which ...

A note on interface dynamics for convection in porous media [Article]
(Elsevier, 20080715)We study the fluid interface problem through porous media given by two incompressible 2D fluids of different densities. This problem is mathematically analogous to the dynamics interface for convection in porous media, ...