Idempotents of small norm

Jayden Mudge, Hung Le Pham

Let $\Gamma$ be a locally compact group. We answer two questions left open in [7] and [9]: i) For abelian $\Gamma$, we prove that if ${\chi }_S\in B(\Gamma )$ is an idempotent with norm $\left\|χ_S \ri…