On The Rationality Of The Spectrum

Debashish Bose, Shobha Madan

Let $\Omega \subset \mathbb{R}$ be a compact set with measure $1$. If there exists a subset $\Lambda \subset \mathbb{R}$ such that the set of exponential functions $E_Λ:=\{e_λ(x) = e^{2πi λx}|_…