Toeplitz subshift whose automorphism group is not finitely generated (Q2833654)

\textit{V. Cyr} and \textit{B. Kra} [Proc. Am. Math. Soc. 144, No. 2, 613--621 (2016; Zbl 1365.37019)] proved that the automorphism group of a topologically transitive shift with subquadratic growth, factored by the subgroup generated by the shift map, is periodic. The paper under review shows that it needs not be finitely generated. More precisely, for every prime number \(p\) and positive integer \(q < p/2\), a simple example of a Toeplitz shift is given. It has subquadratic growth and automorphism group equal to the additive group generated by the non-negative powers of \(p/q\).