G. Berger, Eigenvalue distribution of elliptic operators of second order with Neumannboundary conditions in a snowflake domain, MATH NACHR, 220, 2000, pp. 11-32
Spectral properties of strongly elliptic operators of second order on bound
ed snowflake domains without W-2(1)-extension property are investigated. We
prove that the operators have a pure point spectrum and the asymptotic eig
envalue distributions for the counting function N(lambda) are of Weyl type.
It is shown that the remainder estimate of N(lambda) for Dirichlet and Neu
mann boundary conditions depends on the inner and outer Minkowski dimension
of the boundary partial derivative Omega, respectively.