Enrique A. Sánchez-Pérez

The bicompletion of an asymmetric normed linear space

A biBanach space is an asymmetric normed linear space (X,‖·‖) such that the normed linear space (X,‖·‖s) is a Banach space, where ‖x‖s= max {‖x‖,‖-x‖} for all x∈X. We prove that each asymmetric normed linear space (X,‖·‖) is isometrically isomorphic to a dense subspace of a biBanach space (Y,‖·‖Y). Furthermore the space (Y,‖·‖Y) is unique (up to isometric isomorphism).

The supremum asymmetric norm on sequence algebras: a general framework to measure complexity distances

Abstract Recently, E.A. Emerson and C.S. Jutla (SIAM J. Comput., 1999), have successfully applied complexity of tree automata to obtain optimal deterministic exponential time algorithms for some important modal logics of programs. The running time of these algorithms corresponds, of course, to complexity functions which are potential functions and, thus, they do not belong, in general, to any dual p -complexity space. Motivated by these facts we here introduce and study a very general class of complexity spaces, which provides, in the dual context, a suitable framework to carry out a description of the complexity functions that generate exponential time algorithms. In particular, such spaces can be modelled as biBanach semialgebras which are isometrically isomorphic to the positive cone of the asymmetric normed linear space consisting of bounded sequences of real numbers endowed with the supremum asymmetric norm.

Mathematical properties of weighted impact factors based on measures of prestige of the citing journals

An abstract construction for general weighted impact factors is introduced. We show that the classical weighted impact factors are particular cases of our model, but it can also be used for defining new impact measuring tools for other sources of information—as repositories of datasets—providing the mathematical support for a new family of altmetrics. Our aim is to show the main mathematical properties of this class of impact measuring tools, that hold as consequences of their mathematical structure and does not depend on the definition of any given index nowadays in use. In order to show the power of our approach in a well-known setting, we apply our construction to analyze the stability of the ordering induced in a list of journals by the 2-year impact factor (

Compactness in spaces of p-integrable functions with respect to a vector measure

\hbox {IF}_2

Vector-valued impact measures and generation of specific indexes for research assessment

IF2). We study the change of this ordering when the criterium to define it is given by the numerical value of a new weighted impact factor, in which

Band‐gap creation using quasiordered structures based on sonic crystals

\hbox {IF}_2