On Sets of Large Fourier Transform Under Changes in Domain

Joel Laity, Barak Shani

A function $f:{\mathbb{Z}}_n\to \mathbb{C}$ can be represented as a linear combination $f(x)={\sum }_{\alpha \in {\mathbb{Z}}_n}\hat{f}(\alpha ){\chi }_{\alpha ,n}(x)$ where $\hat{f}$ is the (discrete)…