English

Diffeology and Arithmetic of Irrational Tori

Mathematical Physics 2026-01-05 v3 math.MP

Abstract

The irrational torus, Tα\mathrm{T}_\alpha, originally introduced as a geometric model for quasicrystals, is a foundational object in the theory of diffeology. This paper, after recalling its main algebraic properties, provides a comprehensive analysis of a new geometric invariant for this singular space: the group of flows, Fl(Tα,R)\mathbf{Fl}(\mathrm{T}_\alpha, \mathbf{R}). This invariant, which is trivial for all manifolds, arises as the core of the obstruction to the de Rham theorem in the diffeological setting. We provide a complete computation and geometric interpretation of this group, proving the isomorphism Fl(Tα,R)R×coker(Δα)\mathbf{Fl}(\mathrm{T}_\alpha, \mathbf{R}) \simeq \mathbf{R} \times \mathrm{coker}(\Delta_\alpha).

Keywords

Cite

@article{arxiv.2508.07460,
  title  = {Diffeology and Arithmetic of Irrational Tori},
  author = {Patrick Iglesias-Zemmour},
  journal= {arXiv preprint arXiv:2508.07460},
  year   = {2026}
}

Comments

25 pages, 2 figures. This paper introduces a new geometric invariant, the group of flows, which is specific to diffeology as it is identically trivial for all manifolds. We provide the complete theory and a detailed application to the irrational torus, revealing a deep connection to arithmetic (fixed two misprints an improved a piece of proof)