Estimates for Dirichlet Eigenvalues of Divergence Form Elliptic Operators in Non-Lipschitz Domains.

We obtain estimates for Dirichlet eigenvalues of divergence form elliptic operators −div [A(z)∇f(z)] in bounded non-Lipschitz domains. We propose a method based on the quasiconformal composition operators on Sobolev spaces with application to weighted Poincaré–Sobolev inequalities. [ABSTRACT FROM AUTHOR]