Estimates for Evolutionary Surfaces of Prescribed Mean Curvature.
The rate of growth of the energy integral of a quasiregular mapping is estimated in terms of a special isoperimetric condition on . The estimate leads to new Phragmén-Lindelöf type theorems.
Per ogni soluzione della (1) nel dominio limitato ,, appartenente a e soddisfacente le condizioni (2), si dimostra la maggiorazione (5), valida nell'intorno di ogni punto del contorno; si consente a di essere singolare in .
For a family of elliptic operators with rapidly oscillating periodic coefficients, we study the convergence rates for Dirichlet eigenvalues and bounds of the normal derivatives of Dirichlet eigenfunctions. The results rely on an estimate in for solutions with Dirichlet condition.
Whenever nonlinear problems have to be solved through approximation methods by solving related linear problems a priori estimates are very useful. In the following this kind of estimates are presented for a variety of equations related to generalized first order Beltrami systems in the plane and for second order elliptic equations in . Different types of boundary value problems are considered. For Beltrami systems these are the Riemann-Hilbert, the Riemann and the Poincaré problem, while for elliptic...
We survey recent results concerning estimates of the principal eigenvalue of the Dirichlet -Laplacian and the Navier -biharmonic operator on a ball of radius in and its asymptotics for approaching and . Let tend to . There is a critical radius of the ball such that the principal eigenvalue goes to for and to for . The critical radius is for any for the -Laplacian and in the case of the -biharmonic operator. When approaches , the principal eigenvalue of the Dirichlet...