On the smallest base in which a number has a unique expansion

Pieter Allaart, Derong Kong

Given a real number $x>0$, we determine $q_s(x):=\inf \mathcal{U}(x)$, where $\mathcal{U}(x)$ is the set of all bases $q\in (1,2]$ for which $x$ has a unique expansion of $0$'s and $…