Quasispectra of Solvable Lie Algebra Homomorphisms Into Banach Algebras

Abstract

We propose a noncommutative holomorphic functional calculus on absolutely convex domains for a Banach algebra homomorphism pi of a finite-dimensional solvable Lie algebra g in terms of quasispectra sigma(pi). In particular, we prove that the joint spectral radius of a compact subset in a solvable operator Lie subalgebra coincides with the geometric spectral radius with respect to,a quasispectrum.