English

Equivariant spectral triple for the quantum group $U_q(2)$ for complex deformation parameters

Operator Algebras 2026-01-19 v2 Quantum Algebra

Abstract

Let q=qeiπθ,θ(1,1],q=|q|e^{i\pi\theta},\,\theta\in(-1,1], be a nonzero complex number such that q1|q|\neq 1 and consider the compact quantum group Uq(2)U_q(2). For θQ{0,1}\theta\notin\mathbb{Q}\setminus\{0,1\}, we obtain the KK-theory of the CC^*-algebra C(Uq(2))C(U_q(2)). We construct a spectral triple on Uq(2)U_q(2) which is equivariant under its own comultiplication action. The spectral triple obtained here is even, 4+4^+-summable, non-degenerate, and the Dirac operator acts on two copies of the L2L^2-space of Uq(2)U_q(2). The KK-homology class of the associated Fredholm module is shown to be nontrivial.

Keywords

Cite

@article{arxiv.2102.11473,
  title  = {Equivariant spectral triple for the quantum group $U_q(2)$ for complex deformation parameters},
  author = {Satyajit Guin and Bipul Saurabh},
  journal= {arXiv preprint arXiv:2102.11473},
  year   = {2026}
}

Comments

Title shortened, To appear in Journal of Geometry and Physics

R2 v1 2026-06-23T23:25:38.072Z