2 problems

Let $n$ be a positive integer, let $S\subset\mathbb{R}^n$, and let $f$ be compactly supported. A set $S$ is a non-uniqueness set for compactly supported functions $f$ if the corres…

Let $d$ be the ambient dimension and let $S\subset\mathbb{R}^d$. A set $S$ is a non-uniqueness set for the spherical mean transform in the space of compactly supported functions wh…