Published online by Cambridge University Press: 08 March 2024
For $\mathscr {B} \subseteq \mathbb {N} $, the
$ \mathscr {B} $-free subshift
$ X_{\eta } $ is the orbit closure of the characteristic function of the set of
$ \mathscr {B} $-free integers. We show that many results about invariant measures and entropy, previously only known for the hereditary closure of
$ X_{\eta } $, have their analogues for
$ X_{\eta } $ as well. In particular, we settle in the affirmative a conjecture of Keller about a description of such measures [G. Keller. Generalized heredity in
$\mathcal B$-free systems. Stoch. Dyn. 21(3) (2021), Paper No. 2140008]. A central assumption in our work is that
$\eta ^{*} $ (the Toeplitz sequence that generates the unique minimal component of
$ X_{\eta } $) is regular. From this, we obtain natural periodic approximations that we frequently use in our proofs to bound the elements in
$ X_{\eta } $ from above and below.