Topologically completely positive entropy and zero-dimensional topologically completely positive entropy

Ronnie Pavlov

Published 2015-08-20Version 1

In a previous paper ("A characterization of topologically completely positive entropy for shifts of finite type"), the author gave a characterization for when a $\mathbb{Z}^d$-shift of finite type (SFT) has no nontrivial subshift factors with zero entropy, a property which we here call zero-dimensional topologically completely positive entropy (ZTCPE). In this work, we study the difference between this notion and the more classical topologically completely positive entropy (TCPE) of Blanchard. We show that there are one-dimensional subshifts and two-dimensional SFTs which have ZTCPE but not TCPE. In addition, we show that strengthening the hypotheses of the main result of the aforementioned paper yields a sufficient condition for a $\mathbb{Z}^d$-SFT to have TCPE.