Complexity as a homeomorphism invariant for tiling spaces

Abstract

It is proved that whenever two aperiodic repetitive tilings with finite local complexity have homeomorphic tiling spaces, their associated complexity functions are asymptotically equivalent in a certain sense (which implies, if the complexity is polynomial, that the exponent of the leading term is preserved by homeomorphism). This theorem can be reworded in terms of $d$-dimensional infinite words: if two ${\mathbb{Z}}^d$-subshifts (with the same conditions as above) are flow equivalent, their complexity functions are equivalent. An analogue theorem is proved for the repetitivity function, which is a quantitative measure of the recurrence of orbits in the tiling space. How this result relates to the theory of tilings deformations is outlined in the last part.

Added a the result on the repetitivity function; rearranged some parts of the article; corrected a few minor mistakes. What was previously the last part was shrunk to an outlook. Links to deformations, groupoids and groupoid cohomology will be fully addressed in a future paper