Abstract:
We prove two-term spectral asymptotics for the Riesz means
of the eigenvalues of the Laplacian on a Lipschitz domain
with Robin boundary conditions. The second term is the same
as in the case of Neumann boundary conditions. This is valid
for Riesz means of arbitrary positive order. For orders
at least one and under additional assumptions on the function
determining the boundary conditions, we derive leading order
asymptotics for the difference between Riesz means of Robin
and Neumann eigenvalues.
Keywords:semiclassical asymptotics, Laplacian, Robin boundary conditions.