THEORY OF APPROXIMATION

Author: PAKHROU TIJANI.
Year: 2003.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE MATEMÁTICAS.
Place of preparation: FACULTAD DE MATEMATICAS.

Summary: The argument arose as a main goal the characterization of spaces prehilbert through localization properties centers Chebishev, centers Fermat, p-centros, or, more generally, gamma-centros (gamma standard monotonous). The starting point is to be characterized in terms of centers Chbyshev introducing Amir in his book (Characterizations of Inner Product Spaces, Birkhauser 1986). In the thesis, among other things, proves that characterization is false and Amir are alterantivas to modify it so that real characterizations are obtained. He also raised and resolved problems Approach simultaneous spaces functions built Bochener. The lungs Approach simultaneous are considered from the point of view of Saidi, and Hussein Khalil, as Li and Watson.

Author: GARRANCHO GARCIA PEDRO.
Year: 2003.
University: JAÉN [www.ujaen.es].
Place of defense: FACULTAD DE CIENCIAS SOCIALES Y JURIDICAS.
Place of preparation: FACULTAD DE CIENCIAS SOCIALES Y JURIDICAS.

Summary: It is framed within the theory approximation functions by successions of linear operators. It examines the process when it seeks closer to the k-ésima derivative of a function of class k through succession of derivatives k-ésimas operators linear properties conservative. More specifically examines this process when he presents optimum speed in a sense. To solve the problem, it introduces a new tool as convexity with respect to an ordinary differential equation in any order and a succession of signs.

Author: TORO MODOLELL NAIRA DEL.
Year: 2004.
University: JAÉN [www.ujaen.es].
Place of defense: Edificio Zabaleta, Universidad de Jaén.
Place of preparation: UNIVERSIDAD DE JAÉN.

Summary: THIS IS A WORK OF THEORY OF APPROXIMATION. ITEMS TO BE ABORDAN HAVE ITS ORIGIN IN WORK BETWEEN THE FINAL AND MID-nineteenth S. S. XX BY SEVERAL IMPORTANT MATHEMATICAL, AMONG THOSE TO BE IMPORTANT TO SN BERNSTEIN, C.CH. MÃNTZ, HS Shapiro, YU. BRUNDYI, LB And M. FERGUSON VON GOLITSCHECK. ALL RESULTS ARE STUDYING TO BE RELATED TO THE PROBLEM OF DENSITY OF SUB IN THE CONTEXT OF SPACES QUASI-BANACH. THE MEMORY OF TWO CHAPTERS CONSTA. IN THE FIRST IS DEMUESTRA A NEGATIVE TEOREMA SHAPIRO TYPE VALID FOR SCHEME AND GENERAL APPROACH IS DEMUESTRA ITS POWER TO BE APPLIED IN CONTEXT OF MANY CLASSIC APPROACH. IN ADDITION, HE ESTUDIA A WIDE RANGE OF TEOREMAS NEGATIVE IN PARTICULAR, ARE DEMUESTRA A TEOREMA OF LETARGO OF BERSTEIN OF HILBERT FOR SPACES IN CHAINS SUBESPACIOS GENERAL (INS IMPOSITION OF RESTRICTIONS ON ITS SIZE) IN THE SECOND STRAND EXPLOTA THE USE OF POLINOMIOS OF BERSTEIN IN THE MODIFICATION INTRODUCIDA BY KANTOROVICH IN 1931 FOR POWERS CLEAR IN THE PROBLEM OF APPROXIMATION DIOFÁNTICA (AND APPROACH DIOFÁNTICA CONCURRENT). IN PARTICULAR IS A TEST TEOREMA OF MUNTZ FOR INTERVALOS OF APPROXIMATION DIOFÁNTICA IN DIAMETER TRANSFINITO SMALLER THAN 1.

Author: García de la Rosa Zebenzuí.
Year: 2006.
University: LA LAGUNA [www.ull.es].
Place of defense: Facultad de Matemáticas.
Place of preparation: Departamento de Análisis Matemático de la Universidad de La Laguna.

Summary: The purpose of this dissertation is to extend to several variables of Approximants of Padé and various resusltados classic convergence functions meromorfas