Title: Eigenvalues of compactly perturbed operators via entropy numbers,
Abstract: We derive new estimates for the number of discrete eigenvalues of compactly
perturbed operators on Banach spaces, assuming that the perturbing operator is
an element of a weak entropy number ideal. Our results improve upon earlier
results by the author and by Demuth et al. The main tool in our proofs is an
inequality of Carl. In particular, in contrast to all previous results we do
not rely on tools from complex analysis.