Fredholm spectrum and growth of cohomology groups

Abstract

Let T\in L(E)^{n} be a commuting tuple of bounded linear operators on a complex Banach space E and let \sigma_{F}(T)=\sigma(T)\setminus\sigma_{e}(T) be the non-essential spectrum of T. We show that, for each connected component M of the manifold \mbox{Reg}(\sigma_{F}(T)) of all smooth points of \sigma_{F}(T), there is a number p\in\{0,...,n\} such that, for each point z\in M, the dimensions of the cohomology groups H{}^{p}((z-T)^{k},E) grow at least like the sequence (k^{d})_{k\geq1} with d = dimM.