Special Session 88: Diffusion problems with non-standard growth conditions

Nonlinear elliptic problems with quadratic gradient growth and singular Robin eigenvalues
Francesco Della Pietra
Universita degli studi di Napoli Federico II
Italy
Co-Author(s):    Giuseppina di Blasio, Giuseppe Riey
Abstract:
In the talk I will describe an existence result for Robin boundary value problems modeled on \[ \begin{cases} \Delta u + |\nabla u|^2 + \lambda f(x) = 0 & \text{in } \Omega \ \frac{\partial u}{\partial \nu} + \beta u = 0 & \text{on } \partial\Omega \end{cases} \] where $\Omega$ is a bounded, sufficiently smooth open set in $\mathbb R^N$, $f(x)$ belongs to the Marcinkiewicz space $M^{\frac N2}$ and {$\beta>0$}, under a smallness assumption on the datum $\lambda$. In order to study such problem, I will show several properties of the weighted, singular Robin eigenvalue problem \[ \lambda_{1,f,\gamma}(\Omega)= \inf_{\psi\in H^{1},\;\int_{\Omega}f\psi^{2}=1}\left\{\int_{\Omega}|\nabla \psi|^{2}dx+\gamma\int_{\partial\Omega}\psi^{2}\right\}. \]