Some estimations of positive and negative eigenvalues for an
inhomogeneous membrane
Milutin Dostanić
Abstract
In this paper we give some simple estimates of positive and
negative eigenvalues for the inhomogeneous membrane boundary problem
$$
-\Delta u=\lambda mu,\quad u\,|_{\partial D=0}
$$
if $D\subset R^2$ is a simple connected domain and $m$ is a real bounded
function (possibly changing the sign).
Keywords: Inhomogeneous membrane problem, estimation of eigenvalues.