Spectral triples for subshifts
Abstract
We propose a construction for spectral triple on algebras associated with subshifts. One-dimensional subshifts provide concrete examples Z-actions on Cantor sets. The C*-algebra of this dynamical system is generated by functions in C(X) and a unitary element u implementing the action. Building on ideas of Christensen and Ivan, we give a construction of a family of spectral triples on the commutative algebra C(X). There is a canonical choice of eigenvalues for the Dirac operator D which ensures that [D,u] is bounded, so that it extends to a spectral triple on the crossed product. We study the summability of this spectral triple, and provide examples for which the Connes' distance associated with it on the commutative algebra is unbounded, and some for which it is bounded. We conjecture that our results on the Connes distance extend to the spectral triple defined on the noncommutative algebra.
Keywords
Cite
@article{arxiv.1411.6800,
title = {Spectral triples for subshifts},
author = {Antoine Julien and Ian F. Putnam},
journal= {arXiv preprint arXiv:1411.6800},
year = {2015}
}
Comments
The exposition was shortened at some places and clarified at others. The proof of Theorem 5.8 had a slight gap which we fixed (without consequence for the result)