Beurling-Fourier Algebras and Complexification

Preprint, 2020

In this paper, we develop a new approach that allows to identify the Gelfand spectrum of weighted Fourier algebras as a subset of an abstract complexification of the corresponding group for a wide class of groups and weights. This generalizes some recent results of Ghandehari-Lee-Ludwig-Spronk-Turowska on the spectrum of Beurling-Fourier algebras on some Lie groups. In the case of discrete groups we consider a more general concept of weights and classify them in terms of finite subgroups.