Nonmaximal ideals and the Berkovich space of the algebra of bounded analytic functions

Abstract

We prove that the Berkovich space (or multiplicative spectrum) of the algebra of bounded analytic functions on the open unit disk of an algebraically closed nonarchimedean field contains multiplicative seminorms that are not norms and whose kernel is not a maximal ideal. We also prove that in general these seminorms are not univocally determined by their kernels, and provide a method for obtaining families of different seminorms sharing the same kernel. The relation with the Berkovich space of the Tate algebra is also given.