We study if a time-dependent system is either dynamically stable or unstable, i.e., if the expected value of a positive and discrete observable is a bounded function of time or not. Initially we consider topological ...

The aim of this work is to give some suficient conditions for the existence and multiplicity of the solutions for a class of elliptic problems with sign-changing weight function in unbounded domains, using for this variational ...

In this work we study the differential equation ut = uxx+ f (u); 0 6 x 6 1; t > 0 with homogeneous Dirichlet boundary conditions and f 2C1(R;R) lipschitz and bounded globally and satisfying the following conditions: ...

In this work we study a reaction diffusion problem governed by the p-laplacian with p > 2 and we analyze properties of the continuity of the set of equilibria with respect to the diffusion parameter. We also consider coupled ...

In this dissertation the author proves two results of extensions for IRn of distribution solutions in IRn{0} of the operator Lλ,a = n ∑ i=1 λixi@xi − a, with λ = (λ1, . . . , λn) E Rn ...

In this work we study a reaction-difusion problem with nonlinear Neumann boundary condition. The objective is to present suficient conditions on the diffusion coeficient so that the problem has an stable nonconstant ...

In this work we develop the transformation theory for isothermic surfaces in Euclidean space IR3 due to Darboux and Bianchi. As a consequence, we describe a method for constructing new solutions of the nonlinear system of ...

In this work, we present necessary and suficient conditions for that an operator of Calderón-Zygmund type can be extended to a bounded operator on L2. By using results of interpolation and cancellation conditions on the ...

In this work, we study the global existence of smooth solutions for certain systems of the form ut + f(u)x = Duxx, where u and f are vectors and D is a positive, constant and diagonalizable matrix. We assume that the ...