# Journal of Operator Theory

Volume 73, Issue 2, Spring 2015  pp. 533-546.

On the $C^*$-algebra generated by Toeplitz operators and Fourier multipliers on the Hardy space of a locally compact group

Authors:  Ugur Gul
Author institution:Hacettepe University, Department of Mathematics, 06800, Beytepe, Ankara, Turkey

Summary: Let $G$ be a locally compact abelian Hausdorff topological group which is non-compact and whose Pontryagin dual $\Gamma$ is partially ordered. Let $\Gamma^{+}\subset\Gamma$ be the semigroup of positive elements in $\Gamma$. The Hardy space $H^{2}(G)$ is the closed subspace of $L^{2}(G)$ consisting of functions whose Fourier transforms are supported on $\Gamma^{+}$. In this paper we consider the $C^*$-algebra $C^{*}(\mathcal{T}(G)\cup F(C(\dot{\Gamma^{+}})))$ generated by Toeplitz operators with continuous symbols on $G$ which vanish at infinity and Fourier multipliers with symbols which are continuous on one point compactification of $\Gamma^{+}$ on the Hilbert--Hardy space\break $H^{2}(G)$. We characterize the character space of this $C^*$-algebra using a theorem of Power.

DOI: http://dx.doi.org/10.7900/jot.2014mar12.2055
Keywords: $C^*$-algebras, Toeplitz operators, Hardy space of a locally compact group