Syndetic Riesz sequences
M. Bownik
Abstract: In this talk we show that every subset $\mathcal{S}$ of the torus of positive Lebesgue measure admits a Riesz sequence of exponentials $\{ e^{i\lambda x}\} _{\lambda \in \Lambda}$ in $L^2(\mathcal S)$ such that $\Lambda\subset\mathbb{Z}$ has gaps between consecutive elements bounded by $ \frac{C}{|\mathcal{S}|}$. The proof relies on the solution of the Kadison-Singer problem by Marcus, Spielman, and Srivastava.
The talk is based on a joint work with Itay Londner (University of British Columbia).