English

Dirac operator associated to a quantum metric

Quantum Algebra 2023-05-16 v2 General Relativity and Quantum Cosmology

Abstract

We construct a canonical geometrically realised Connes spectral triple or `Dirac operator' D ⁣ ⁣ ⁣/D\!\!\!/ from the data of a quantum metric gΩ1AΩ1g\in \Omega^1\otimes_A\Omega^1 and quantum Levi-Civita bimodule connection, at the pre-Hilbert space level. Here AA is a possibly noncommutative coordinate algebra, Ω1\Omega^1 a bimodule of 1-forms and the spinor bundle is S=AΩ1S=A\oplus\Omega^1. When applied to graphs or lattices, we essentially recover a Dirac operator previously proposed by Bianconi but now as a geometrically realised spectral triple. We also apply the construction to the fuzzy sphere and to 2×22\times 2 matrices with their standard quantum Riemannian geometries. We also propose how D ⁣ ⁣ ⁣/D\!\!\!/ can be minimally coupled to an external potential.

Keywords

Cite

@article{arxiv.2302.05891,
  title  = {Dirac operator associated to a quantum metric},
  author = {Shahn Majid},
  journal= {arXiv preprint arXiv:2302.05891},
  year   = {2023}
}

Comments

24 pages AMS-Latex. Some minor corrections and clarifications, simplifying the graph case

R2 v1 2026-06-28T08:38:01.910Z