arXiv subjects

Youssef Jabri

Publications and source records attributed to Youssef Jabri.

3 recordsLinked to original sources

arXiv2002

A nonsmooth variational approach to differential problems. A case study of nonresonance under the first eigenvalue for a strongly nonlinear elliptic problem

We adapt a technique of nonsmooth critical point theory developed by Degiovanni-Zani for a semilinear problem involving the Laplacian to the the case of the $p$-Laplacian. We suppose only coercivity conditions on the potential and impose no growth condition of the nonlinearity. The coercivity is obtained using similar nonresonance conditions to [Mawhin-Ward-Willem] and to [Landesman-Lazer] in two different results and using some comparison functions and comparison spaces in a third one. It is also shown that neither of the three theorems implies the two others.

math.FA↗

arXiv2002

Nonsmooth Critical Point Theorems Without Compactness

We establish an abstract critical point theorem for locally Lipschitz functionals that does not require any compactness condition of Palais-Smale type. It generalizes and unifies three other critical point theorems established in [Jabri-Moussaoui] for $C^{1}$-functionals under slightly stronger assumptions. Our approach uses continuous selections of multivalued mappings.

math.FA↗

arXiv1999

On the Linking Principle

We give a linking theorem that strengthens and unifies some many minimax theorems including Ambrosetti-Rabinowitz ``mountain pass theorem'', Rabinowitz ``multidimensional mountain pass theorem'', Rabinowitz ``saddle point theorem'' and Silva's variants of these results. We focus our attention especially on ``the limiting case'', known to be true for the mountain pass principle, where some information on the location of the critical points is given. Two forms of this theorem are given: the first one is established via a deformation lemma and we use Ekeland's variational principle to get the second one.

math.FA↗