Approximation of Quantum Tori by Finite Quantum Tori for the Quantum Gromov-Hausdorff Distance
arXiv:math/0310214
Abstract
The statement that one can approximate a quantum torus by some twisted convolution C*-algebra of a (finite) quotient of Z^d can be found in the physics literature dealing with quantum field theory and M-theory. In this paper, we show that indeed the quantum tori are limits of such finite dimensional C*-algebras for the quantum Gromov-Hausdorff distance for compact quantum metric spaces introduced by Rieffel, when one chooses the right metric structures. The proof uses a mild extension of a result by Ramazan on continuous fields of C*-algebras obtained from groupoid C*-algebras, and extends on Rieffel's work on the continuity of the quantum tori for the quantum Gromov-Hausdorff distance. We also show that one can collapse a quantum torus to a lower dimensional quantum torus.
arXiv commentPublished version (Journal of Functional Analysis), 33 pages. This version proves a more general statement of the main result. The older version v2 contains more details regarding the use of groupoids in the proof of the main result