We consider the problemwhere $\Omega \subset {ℝ}^3$ is a smooth and bounded domain, $\epsilon ,{\gamma }_1,{\gamma }_2\>0,$$v,V:\Omega \to ℝ...$

We give sufficient conditions for the existence of global small solutions to the quasilinear dissipative hyperbolic equation $$u_{tt}+2u_t-a_{ij}(u_t,\nabla u){\partial }_i{\partial }_{j}u=f$$ corresponding to initial values and source terms of sufficiently small size, as well as of small solutions to the corresponding stationary version, i.e. the quasilinear elliptic equation $$-a_{ij}(0,\nabla v){\partial }_i{\partial }_{j}v=h.$$ We then give conditions for the convergence, as $t\to \infty$, of the solution of the evolution equation to its stationary state.

This paper is devoted to an analysis of vortex-nucleation for a Ginzburg-Landau functional with discontinuous constraint. This functional has been proposed as a model for vortex-pinning, and usually accounts for the energy resulting from the interface of two superconductors. The critical applied magnetic field for vortex nucleation is estimated in the London singular limit, and as a by-product, results concerning vortex-pinning and boundary conditions on the interface are obtained.

We consider a model for flow in a porous medium with a fracture in which the flow in the fracture is governed by the Darcy−Forchheimerlaw while that in the surrounding matrix is governed by Darcy’s law. We give an appropriate mixed, variational formulation and show existence and uniqueness of the solution. To show existence we give an analogous formulation for the model in which the Darcy−Forchheimerlaw is the governing equation throughout the domain. We show existence and uniqueness of the solution...

The aim of this paper is to characterize the u.s.c. (resp. l.s.c.) viscosity sub (resp. super) solutions of the Laplacian which do not take the value $+\mathrm{\infty }$ (resp. $-\mathrm{\infty }$) as precisely the sub (resp. super) harmonic functions.

In this paper we consider the Neumann problem involving a critical Sobolev exponent. We investigate a combined effect of the coefficient of the critical Sobolev nonlinearity and the mean curvature on the existence and nonexistence of solutions.

This paper deals with phase transitions corresponding to an energy which is the sum of a kinetic part of $p$-Laplacian type and a double well potential $h_0$ with suitable growth conditions. We prove that level sets of solutions of ${\Delta }_{p}u=h_0^{\text{'}}\left(u\right)$ possessing a certain decay property satisfy a mean curvature equation in a suitable weak viscosity sense. From this, we show that, if the above level sets approach uniformly a hypersurface, the latter has zero mean curvature.

In the present paper we survey some recents results concerning existence of semiclassical standing waves solutions for nonlinear Schrödinger equations. Furthermore, from Maxwell's equations we derive a nonlinear Schrödinger equation which represents a model of propagation of an electromagnetic field in optical waveguides.

In this paper we prove that every weak and strong local minimizer $u\in W^{1,2}(\Omega ,{ℝ}^3)$ of the functional $I\left(u\right)={\int }_{\Omega }{\left|Du\right|}^2+f\left(\mathrm{Adj}Du\right)+g\left(\det Du\right),$ where $u:\Omega \subset {ℝ}^3\to {ℝ}^3$, f grows like ${\left|\mathrm{Adj}Du\right|}^p$, g grows like ${\left|\det Du\right|}^q$ and 1<q<p<2, is $C^{1,\alpha }$ on an open subset ${\Omega }_0$ of Ω such that $\mathrm{𝑚𝑒𝑎𝑠}(\Omega \setminus {\Omega }_0)=0$. Such functionals naturally arise from nonlinear elasticity problems. The key point in order to obtain the partial regularity result is to establish an energy estimate of Caccioppoli type, which is based on an appropriate choice of the test functions. The limit case $p=q\le 2$ is also treated for weak local minimizers. ...

We prove the existence of solutions to $-\text{div}a\left(x,\text{grad}u\right)=f$, together with appropriate boundary conditions, whenever $a\left(x,e\right)$ is a maximal monotone graph in $e$, for every fixed $x$. We propose an adequate setting for this problem, in particular as far as measurability is concerned. It consists in looking at the graph after a ${45}^{\circ }$ rotation, for every fixed $x$; in other words, the graph $d\in a\left(x,e\right)$ is defined through $d-e=\phi \left(x,d+e\right)$, where $\phi$ is a Carathéodory contraction in ${\mathbb{R}}^N$. This definition is shown to be equivalent to the fact that $a(x,\cdot )$ is pointwise monotone...