Scielo RSS <![CDATA[Proyecciones (Antofagasta)]]> vol. 24 num. 2 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<b>NONRESONANCE BETWEEN TWO EIGENVALUES NOT NECESSARILY CONSECUTIVE</b>]]> In this paper we study the existence of solutions for a semilinear elliptic problem in case two eigenvalues are not necessarily consecutive<hr/>Dans cet article, nous étudions l’existence des solutions entre deux valeurs propres non nécessairement consecutives d’un probléme semi-linéaire elliptique <![CDATA[<b>A NEW FORM OF FUZZY </b><b>ß</b><b>-COMPACTNESS</b>]]> A new form of ß-compactness is introduced in L-topological spaces by means of ß-open L-sets and their inequality where L is a complete de Morgan algebra. This new form doesn’t rely on the structure of basis lattice L. It can also be characterized by means of ß-closed L-sets and their inequality. When L is a completely distributive de Morgan algebra, its many characterizations are presented. Meanwhile countable ß-compactness and the ß-Lindelöf property are also researched <![CDATA[<b>INERTIAL RELATIVITY - A FUNCTIONAL ANALYSIS REVIEW</b>]]> The theory of special relativity (TSR) exhibits an unquestionable success, at the expense of an unresolved axiomatic conflict with functional analysis and operator theory, as this paper demonstrates. These mathematical disciplines -amongst the newest developments in the field- could not possibly be incorporated into the original formulation of the TSR because they were in an incipient state at the turn of the 20th century when the TSR was being formulated, maturing only decades later <![CDATA[<b>S</b><b><sub>ß</sub></b><b>-COMPACTNESS IN L-TOPOLOGICAL SPACES</b>]]> In this paper, the notion of Sß-compactness is introduced in Ltopological spaces by means of open ßà-cover. It is a generalization of Lowen’s strong compactness, but it is different from Wang’s strong compactness. Ultra-compactness implies Sß-compactness. Sß-compactness implies fuzzy compactness. But in general N-compactness and Wang’s strong compactness need not imply Sß-compactness <![CDATA[<b>STRATEGY FOR TO STABILIZE NON LINEAR SYSTEMS THROUGH DIRECTIONAL CONTROLS</b>]]> For a non linear system, with an isolated and non asymptotically stable equilibrium point, we had obtained a control strategy which disturb the system so that the dynamic move locally towards the equilibrium point. We consider the linearization of the system and feedback directional controls <![CDATA[<b>ON FOLIATIONS WITH RATIONAL FIRST INTEGRAL</b>]]> We use the Kodaira’s classification of relatively minimal elliptic fibrations to prove that a holomorphic foliation in CP² with a dicritical compact elliptic curve has rational first integral