We study the family of piecewise linear differential systems in the plane with two pieces separated by a cubic curve. Our main result is that 7 is a lower bound for the Hilbert number of this family. In order to get our ...

We continue the investigation of the algebraic and topological structure of the algebra of Colombeau generalized functions with the aim of building up the algebraic basis for the theory of these functions. This was started ...

El famoso Teorema de De Rham establece un isomorfismo entre los grupos de cohomología de De Rham y los grupos de cohomología singular de una variedad diferenciable M. Estos pueden ser “detectados” mediante formas diferenciales. ...

We study the coincidence theory of maps between two manifolds of the same dimension from an axiomatic viewpoint. First we look at coincidences of maps between manifolds where one of the maps is orientation true, and give ...

Esta tesis trata del Problema de Equivalencia para distribuciones y estructuras geométricas asociadas, o sub-estructuras. Repasamos el método de equivalencia de Cartan y lo comparamos con el Método de Prolongación de Tanaka, ...

En este trabajo demostramos que todo grupoide doble de Lie con acción medular propia esta completamente determinado por una factorización de un cierto grupoide de Lie diagonal canónicamente definido. Tambien, estudiamos ...

A temporally global solution, if it exists, of a nonautonomous ordinary differential equation need not be periodic, almost periodic or almost automorphic when the forcing term is periodic, almost periodic or almost ...

In order to study tensor fields of type (0,2) on manifolds and fibrations we introduce a new formalism that we called s-space. The s-spaces induced a one to one correspondence between the (0,2) tensor fields and some ...