For differential games of fixed duration of linear dynamical systems with nonquadratic payoff functionals, it is proved that the value and the optimal strategies as saddle point exist whenever the associated pseudo-Riccati equation has a regular solution $P\left(t,x\right)$. Then the closed-loop optimal strategies are given by $u\left(t\right)=-R^{-1}{B}^{\ast }P\left(t,x\left(t\right)\right),v\left(t\right)=-S^{-1}{C}^{\ast }P\left(t,x\left(t\right)\right)$. For differential game problems of Mayer type, the existence of a regular solution to the pseudo-Riccati equation is proved under certain assumptions and a constructive expression of that solution can be found by solving an algebraic equation with time parameter.

We study in the framework of Orlicz Sobolev spaces $W_0^1{L}_M\left(\Omega \right)$, the existence of entropic solutions to the nonlinear elliptic problems: $-\text{div}a\left(\text{x,u,}\nabla u\right)+\text{div}\Phi \left(u\right)=f\text{in}\Omega$, for the case where the second member of the equation $f\in L^1\left(\Omega \right)$, and $\Phi \in {\left(C^0\left(ℝ\right)\right)}^N$.

We derive a nontrivial solution for a Neumann noncoercive hemivariational inequality using the critical point theory for locally Lipschitz functionals. We use the Mountain-Pass theorem due to Chang (1981).