One Bit Sensing, Discrepancy, and Stolarsky Principle

Understand

A sign-linear one bit map from the $ d$-dimensional sphere $ \mathbb S ^{d}$ to the $ n$-dimensional Hamming cube $ H^n= \{ -1, +1\} ^{n}$ is given by $$ x \to \{ \mbox{sign} (x \cdot z_j) \;:\; 1\leq j \leq n\} $$ where $ \{z_j\} \subset \mathbb S ^{d}$.

• For $ 0 < \delta < 1$, we estimate $ N (d, \delta )$, the smallest integer $ n$ so that there is a sign-linear map which has the $ \delta $-restricted isometric property, where we impose normalized geodesic distance on $ \mathbb S ^{d}$, and Hamming metric on $ H^n$.
• Up to a polylogarithmic factor, $ N (d, \delta ) \approx \delta^{-2 + \frac2{d+1}}$, which has a dimensional correction in the power of $ \delta $.
• This is a question that arises from the one bit sensing literature, and the method of proof follows from geometric discrepancy theory.