Extension d'un Théorème de Harte et Applications aux Algèbres de Jordan-Banach

In this paper we study some questions related to spectral theory in Jordan-Banach algebras. Firstly, we introduce the notion of exponential spectrum and then we extend to Jordan-Banach algebras a theorem due to Robin Harte in the associative case. Secondly, these results are used to get a theorem on spectral perturbation by inessential elements in Jordan-Banach algebras.