Información del autor
Autor Romero Ruiz del Portal, Francisco |
Documentos disponibles escritos por este autor (48)
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Hernández Corbato, Luis ; Le Calvez , Patrice ; Romero Ruiz del Portal, Francisco | Geometry & Topology Publications, Univ Warwick, Mathematics Inst | 2013This article includes an almost self-contained exposition on the discrete Conley index and its duality. We work with a locally defined homeomorphism f in R-d and an acyclic continuum X, such as a cellular set or a fixed point, invariant under f [...]texto impreso
Cuchillo Ibáñez, Eduardo ; Morón, Manuel A. ; Romero Ruiz del Portal, Francisco | Editorial Complutense | 1994This interesting and well-written survey article is devoted to the class P of topological spaces in which components and quasi-components coincide. This class includes the compact Hausdorff spaces and the locally connected spaces. It also inclu[...]texto impreso
Carabantes Alarcón, David ; Ancochea Soto, Eumenio ; Arias Astray, Andrés ; Dupont Sfez, Samuelle ; Iglesias Recuero, Silvia ; Manjón-Cabeza Olmeda, Araceli ; Martín Martín, José Oliver ; Montero de Juan, Francisco Javier ; Romero Ruiz del Portal, Francisco ; San Andrés Moya, Margarita ; Sastre Castillo, Miguel Ángel ; Tirado Fernández, Francisco | 2018-06-30El Aprendizaje Servicio es una estrategia docente necesaria para el desarrollo de iniciativas de emprendimiento e innovación social, que partan desde la Universidad, y que se puedan incorporar en las diferentes áreas de conocimiento de la UCMtexto impreso
Hernández Corbato, Luis ; Ortega, Rafael ; Romero Ruiz del Portal, Francisco | Cambridge Univ Press | 2012Let h : R-2 -> R-2 be a dissipative and orientation preserving homeomorphism having an asymptotically stable fixed point. Let U be the region of attraction and assume that it is proper and unbounded. Using Caratheodory's prime ends theory one c[...]texto impreso
Given an orientation-preserving homeomorphism of the plane, a rotation number can be associated with each locally attracting fixed point. Assuming that the homeomorphism is dissipative and the rotation number vanishes we prove the existence of a[...]texto impreso
A bimorphism is both an epimorphism and a monomorphism. If every bimorphism is an iso then the given category is said to be balanced. Such notions are studied in several contexts (pro-categories, pro-homotopy, shape, proper homotopy). The refere[...]texto impreso
The authors deal with the question of whether the sets of shape and homotopy types of FANRs are countable. FANRs can be considered as a natural generalization of ANRs; thus the authors' starting point consists of results on the countability of t[...]texto impreso
Giraldo, A. ; Morón, Manuel A. ; Romero Ruiz del Portal, Francisco ; Rodríguez Sanjurjo, José Manuel | Elsevier Science B.V. (North-Holland) | 2001-09-07We show in this paper how to represent intrinsically Cech homology of compacta, in terms of inverse limits of discrete approximations. We establish some relations between inverse limits and non-continuous homotopies and, as a consequence, we get[...]texto impreso
The author proves that if f is an orientation reversing homeomorphism of the plane and p is an isolated and stable fixed point of f then the fixed point index of f at p is equal to 1 . In the orientation preserving case this result was obta[...]texto impreso
Let U c R2 be an open subset and let f :U ? f (U) c R2 be a homeomorphism. Let M = M1 U· · ·U Mr C U be a disjoint union of discs that isolates the invariant compactum K. The aimof this paper is to study the dynamics of f in K and to use the fix[...]texto impreso
Let X be a locally compact metric absolute neighbourhood retract for metric spaces, U subset of X be an open subset and f:U --> X be a continuous map. The aim of the paper is to study the fixed point index of the map that f induces in the hypers[...]texto impreso
Let X be a locally compact metric absolute neighbourhood retract for metric spaces, U?X be an open subset and f :U?X be a continuous map. The aim of the paper is to study the fixed point index of the map that f induces in the y perspace of X. Fo[...]texto impreso
Let U be an open subset of R2 and let f :U ? R2 be a local homeomorphism. Let p € U be a non-repeller 4xed point of f suchth at {p} is an isolated invariant set. We introduce a particular class of index pairs for {p} that we call generalized 4lt[...]texto impreso
Hernández Corbato, Luis ; Romero Ruiz del Portal, Francisco | American Institute of Mathematical Sciences | 2015-07We characterize the sequences of fixed point indices {i(f(n) ,p)} n > = 1 of fixed points that are isolated as an invariant set for a continuous map f in the plane. In particular, we prove that the sequence is periodic and i(f(n) ,p) = 0. This[...]texto impreso
In this paper we apply the generalized degree introduced by Geba, Massabo and Vignoli, in [3], to extend the notion of complementing maps defined by Fitzpatrick, Massabo and Pejsachowicz, in [1] and [2]. On the other hand, we obtain, in low dime[...]texto impreso
We present a generalized degree theory for continuous maps f (D, 9D) - (E, E\{0}), where E is a normed vectorial space, Dis an open subset of Rk xEsuch that p, (D) is bounded in Rk and f is a compact perturbation of the second projection p2 : Rk[...]texto impreso
The purpose of this paper is to seek utility functions satisfying a weak condition which guarantees that the utility optimum always belongs to the compromise set. This set is a special subset of the attainable or feasible set, which is generated[...]texto impreso
Let U subset of R-2 be an open subset, f : U -> f (U) subset of R-2 be an orientation reversing homeomorphism and let 0 is an element of U be an isolated, as a periodic orbit, fixed point. The main theorem of this paper says that if the fixed p[...]texto impreso
Le Calvez, Patrice ; Romero Ruiz del Portal, Francisco ; Salazar, J. M. | Oxford University Press | 2010Let U subset of R-3 be an open set and f : U -> f(U) subset of R-3 be a homeomorphism. Let p is an element of U be a fixed point. It is known that if {p} is not an isolated invariant set, then the sequence of the fixed-point indices of the iter[...]texto impreso
Le Calvez , Patrice ; Romero Ruiz del Portal, Francisco ; Salazar, J. M. | Oxford University Press | 2010Let U ? R3 be an open set and f : U ? f(U) ? R3 be a homeomorphism. Let p ? U be a fixed point. It is known that if {p} is not an isolated invariant set, then the sequence of the fixedpoint indices of the iterates of f at p, (i(fn, p))n1, is, in[...]texto impreso
A morphism of a category which is simultaneously an epimorphism and a monomorphism is called a bimorphism. In (Dydak and Ruiz del Portal (Monomorphisms and epimorphisms in pro-categories, preprint)) we gave characterizations of monomorphisms (re[...]texto impreso
Let f : U ?R2 be a continuous map, where U is an open subset of R2. We consider a fixed point p of f which is neither a sink nor a source and such that ?p? is an isolated invariant set. Under these assumption we prove, using Conley index meth[...]texto impreso
Cuchillo Ibáñez, Eduardo ; Morón, Manuel A. ; Romero Ruiz del Portal, Francisco | Auburn University | 1992In this paper we use the lower semifinite topology in hyperspaces to obtain examples in topology such as pseudocompact spaces not countably compact, separable spaces not Lindelöf and in a natural way many spaces appear which are T0 but not T1. W[...]texto impreso
A morphism of a category which is simultaneously an epimorphism and a monomorphism is called a bimorphism. We give haracterizations of monomorphisms (respectively, epimorphisms) in pro-category pro-C, provided C has direct sums (respectively,pus[...]texto impreso
Morón, Manuel A. ; Romero Ruiz del Portal, Francisco | Japanese Association of mathematical Sciences | 1994We give a new description of the shape category of paracompact spaces in terms of multivalued maps that allows us to find new characterizations, in some way intrinsic, of calmness, movability and maps inducing shape equivalences, and to extend t[...]