Beurling-Fourier algebras on compact groups: spectral theory

Abstract

For a compact group $G$ we define the Beurling-Fourier algebra $A_{\omega }(G)$ on $G$ for weights $\omega$ defined on the dual $\what G$ and taking positive values. The classical Fourier algebra corresponds to the case $\omega$ is the constant weight 1. We study the Gelfand spectrum of the algebra realizing it as a subset of the complexification $G_{\mathbb{C}}$ defined by McKennon and Cartwright and McMullen. In many cases, such as for polynomial weights, the spectrum is simply $G$. We discuss the questions when the algebra $A_{\omega }(G)$ is symmetric and regular. We also obtain various results concerning spectral synthesis for $A_{\omega }(G)$.

37 pages