  This paper provides results for eigencurves associated with self-adjoint
linear elliptic boundary value problems. The elliptic problems are treated as a
general two-parameter eigenproblem for a triple (a, b, m) of continuous
symmetric bilinear forms on a real separable Hilbert space. Variational
characterizations of the eigencurves associated with (a, b, m) are given and
various orthogonality results for corresponding eigenspaces are found.
Continuity and differentiability, as well as asymptotic results, for these
eigencurves are proved. These results are then used to provide a geometric
description of the eigencurves.
