Spectrality of Product Sets with a Perturbed Interval Factor

Aditya Ramabadran, Johannes van Vliet

A set $\hat{I}\text{c◯}\subset {\mathbb{R}}^d$ is said to be spectral if $L^2(\hat{I}\text{c◯})$ admits an orthogonal basis of exponentials. While the product of spectral sets is known to be spectral, the conve…