Rate-independent problems are considered, where the stored energy density is a function of the gradient. The stored energy density may not be quasiconvex and is assumed to grow linearly. Moreover, arbitrary behaviour at infinity is allowed. In particular, the stored energy density is not required to coincide at infinity with a positively 1-homogeneous function. The existence of a rate-independent process is shown in the so-called energetic formulation.

This paper discusses the existence and multiplicity of solutions for a class of $p\left(x\right)$-Kirchhoff type problems with Dirichlet boundary data of the following form $$\left\}\begin{array}{cc}-\left(a+b{\int }_{\Omega }\frac{1}{p\left(x\right)}{\left|\nabla u\right|}^{p\left(x\right)}dx\right){\mathrm{div}\left(\right|\nabla u|}^{p\left(x\right)-2}\nabla u)=f(x,u),\hfill & in\Omega \hfill \\ u=0\hfill & on\partial \Omega ,\hfill \end{array}\right.$$ where $\Omega$ is a smooth open subset of ${ℝ}^N$ and $p\in C\left(\overline{\Omega }\right)$ with $N<p^{-}={inf}_{x\in \Omega }p\left(x\right)\le p^{+}={sup}_{x\in \Omega }p\left(x\right)<+\infty$, $a$, $b$ are positive constants and $f:\overline{\Omega }\times ℝ\to ℝ$ is a continuous function. The proof is based on critical point theory and variable exponent Sobolev space theory.

The purpose of this paper is to extend the Díaz-Saá’s inequality for the unbounded domains as RN.The proof is based on the Picone’s identity which is very useful in problems involving p-Laplacian. In a second part, we study some properties of the first eigenvalue for a system of p-Laplacian. We use Díaz-Saá’s inequality to prove uniqueness and Egorov’s theorem for the isolation. These results generalize J. Fleckinger, R. F. Manásevich, N. M. Stavrakakis and F. de Thélin’s work [9] for the first...

Soit $\mathbf{F}$ le faisceau des sursolutions variationnelles d’un opérateur différentiel elliptique du second ordre à coefficients ${\mathbf{L}}_{\mathrm{loc}}^{\infty }$. Soit $\widehat{\mathbf{F}}$ le faisceau des régularitées essentielles inférieures des éléments de $\mathbf{F}$. On démontre que $\widehat{\mathbf{F}}$ est contenu dans un seul préfaisceau ${\mathbf{F}}^{*}$ maximal de cônes convexes de fonctions s.c.i. $\&gt;-\infty$ vérifiant le principe du minimum sur une base d’ouverts suffisamment petits. On démontre que ${\mathbf{F}}^{*}$ possède toutes les bonnes propriétés d’une théorie locale du potentiel.