An Error Estimate Uniform in Time for Spectral Galerkin Approximations for the Equations for the Motion of a Chemical Active Fluid

Sin resume

The Initial Value Problem for the Equations of Magnetohydrodynamic Type in Non-Cylindrical Domain

Sin resume

Magneto-micropolar fluid motion: existence of weak solutions

Sin resume

Nonsmooth multiobjective fractional programming with generalized convexity

En el artículo estudiamos una clase de problemas fraccionales multiobjetivos no convexos y no diferenciables. Usamos la transformación propuesta por Dinkelbach [2] y Jagannathan [4] y obtenemos condiciones de optimalidad para soluciones débilmente eficientes de dichos problemas. Además, definimos un problema dual y establecemos algunos resultados sobre dualidad. Para lograrlo, utilizamos una noción de convexidad generalizada llamada KT-invexidad. El artículo generaliza los resultados obtenidos por Osuna-Gómez et al. en [6], en donde los autores consideran problemasIn this paper we study a class of nonconvex and nondifferentiable multiobjective fractional problems. We use the transformation proposed by Dinkelbach [2] and Jagannathan [4] and we obtain optimality conditions for weakly efficient solutions for these problems. Furthermore, we define a dual problem and we establish some results on duality. To obtain our results, we use a notion of generalized convexity, called KT-invexity. Our paper generalizes the results given by Osuna-Gómez et al. in [6], where the authors considered smooth problems.    &nbsp

Sobre la diferenciabilidad de funciones en espacios de Banach

  Se da un criterio que establece la diferenciabilidad de una función f : X → Y , donde X y Y son espacios de Banach. Este criterio se aplica además para obtener las reglas usuales del cálculo diferencial de una forma elemental, y también para obtener la diferenciabilidad de algunas normas de espacios funcionales clásicos.        A criterion for the differentiability of a function f : X → Y , where X and Y are both Banach spaces, is given. Moreover, this criterion is applied to obtain the usual rules of the differential calculus of an elementary fashion and to obtain the differentiability of some norms of classical functional spaces. &nbsp

Explicit calculation of multi-fold contour integrals of certain ratios of Euler gamma functions. Part 1

In this paper we proceed to study properties of Mellin-Barnes (MB) transforms of Usyukina-Davydychev (UD) functions. In our previous papers [Nuclear Physics B 870 (2013) 243], [Nuclear Physics B 876 (2013) 322] we showed that multi-fold Mellin-Barnes (MB) transforms of Usyukina-Davydychev (UD) functions may be reduced to two-fold MB transforms and that the higher-order UD functions were obtained in terms of a differential operator by applying it to a slightly modified first UD function. The result is valid in $d=4$ dimensions and its analog in $d=4-2\varepsilon$ dimensions exits too [Theoretical and Mathematical Physics 177 (2013) 1515]. In [Nuclear Physics B 870 (2013) 243] the chain of recurrent relations for analytically regularized UD functions was obtained implicitly by comparing the left hand side and the right hand side of the diagrammatic relations between the diagrams with different loop orders. In turn, these diagrammatic relations were obtained due to the method of loop reduction for the triangle ladder diagrams proposed in 1983 by Belokurov and Usyukina. Here we reproduce these recurrent relations by calculating explicitly via Barnes lemmas the contour integrals produced by the left hand sides of the diagrammatic relations. In such a way we explicitly calculate a family of multi-fold contour integrals of certain ratios of Euler gamma functions. We make a conjecture that similar results for the contour integrals are valid for a wider family of smooth functions which includes the MB transforms of UD functions.Comment: 7 pages, 1 figure, minor changes in the text; accepted for publication in Nuclear Physics

Continuous-Time Multiobjective Optimization Problems via Invexity

We introduce some concepts of generalized invexity for the continuous-time multiobjective programming problems, namely, the concepts of Karush-Kuhn-Tucker invexity and Karush-Kuhn-Tucker pseudoinvexity. Using the concept of Karush-Kuhn-Tucker invexity, we study the relationship of the multiobjective problems with some related scalar problems. Further, we show that Karush-Kuhn-Tucker pseudoinvexity is a necessary and suffcient condition for a vector Karush-Kuhn-Tucker solution to be a weakly efficient solution

Numerical study of systems of fuzzy nonlinear equations

En este trabajo estudiamos la resolución numérica de sistemas de ecuaciones no lineales difusas. Más precisamente describimos, analizamos y simulamos métodos numéricos, tales como el método de Newton, con el fin de aproximar de forma eficiente las soluciones a dichos problemas. Una de las características principales de este tipo de problemas es que las técnicas analíticas estándares de soluciones no son adecuadas para resolverlos. Por esta razón, en este artículo nos centramos en el estudio de los resultados conocidos para los métodos numéricos clásicos y en su adaptación a la resolución de problemas difusos.  In this work we study the numerical resolution of systems of fuzzy nonlinear equations. More precisely, we describe, analyze and simulate numerical methods, such as Newton method, in order to approximate efficiently the solutions to such problems. One of the main issues of this type of problems is that the standard analytical techniques for finding solutions, are not appropriate to resolve them. For this reason, in this paper we focus in the study of known results for the classical methods and their adaptation to the resolution of fuzzy problems