English

A reconstruction theorem for Connes-Landi deformations of commutative spectral triples

Mathematical Physics 2026-01-15 v3 High Energy Physics - Theory math.MP Operator Algebras Quantum Algebra

Abstract

We formulate and prove an extension of Connes's reconstruction theorem for commutative spectral triples to so-called Connes-Landi or isospectral deformations of commutative spectral triples along the action of a compact Abelian Lie group GG, also known as toric noncommutative manifolds. In particular, we propose an abstract definition for such spectral triples, where noncommutativity is entirely governed by a deformation parameter sitting in the second group cohomology of the Pontrjagin dual of GG, and then show that such spectral triples are well-behaved under further Connes-Landi deformation, thereby allowing for both quantisation from and dequantisation to GG-equivariant abstract commutative spectral triples. We then use a refinement of the Connes-Dubois-Violette splitting homomorphism to conclude that suitable Connes-Landi deformations of commutative spectral triples by a rational deformation parameter are almost-commutative in the general, topologically non-trivial sense.

Keywords

Cite

@article{arxiv.1408.4429,
  title  = {A reconstruction theorem for Connes-Landi deformations of commutative spectral triples},
  author = {Branimir Ćaćić},
  journal= {arXiv preprint arXiv:1408.4429},
  year   = {2026}
}

Comments

AMS-LaTeX, 41 pp. V3: Corrected the orientability condition in the definition of theta-commutative spectral triple, including a new appendix with a proof of consistency with the relevant commutative case