When we consider surfaces of prescribed mean curvature
with
a one-to-one orthogonal projection onto a plane, we have to study the nonparametric
-surface equation.
Now the
-surfaces
with a one-to-one central projection onto a plane lead to an interesting elliptic differential equation;
in the case
this PDE was invented by T. Radó. We establish the uniqueness of the Dirichlet problem for
this
-surface
equation in central projection and develop an estimate for the maximal deviation of large
-surfaces from
their boundary values, resembling an inequality by J. Serrin. We also provide a Bernstein-type
result for the case
and classify the entire solutions of the minimal surface equation
in central projection. We also solve the Dirichlet problem for
by a variational method. We solve the Dirichlet problem for nonvanishing
with
compact support via a nonlinear continuity method, and we construct large
-surfaces
bounding extreme contours by an approximation. Finally, we
solve the Dirichlet problem on discs for the nonparametric
-surface
equation in central projection under certain restrictions for the mean curvature.
Dedicated to the memory of Professor
Stefan Hildebrandt in gratitude
Keywords
surfaces of prescribed mean curvature, solution of the
Dirichlet problem, $H\mskip-2mu$-surface equation in
central projection, large $H\mskip-2mu$-surfaces for
Plateau's problem