English

L\'evy-Khintchine decompositions for generating functionals on algebras associated to universal compact quantum groups

Quantum Algebra 2018-10-04 v4

Abstract

We study the first and second cohomology groups of the ^*-algebras of the universal unitary and orthogonal quantum groups UF+U_F^+ and OF+O_F^+. This provides valuable information for constructing and classifying L\'evy processes on these quantum groups, as pointed out by Sch\"urmann. In the case when all eigenvalues of FFF^*F are distinct, we show that these ^*-algebras have the properties (GC), (NC), and (LK) introduced by Sch\"urmann and studied recently by Franz, Gerhold and Thom. In the degenerate case F=IdF=I_d, we show that they do not have any of these properties. We also compute the second cohomology group of Ud+U_d^+ with trivial coefficients -- H2(Ud+,ϵCϵ)Cd21H^2(U_d^+,{}_\epsilon\Bbb{C}_\epsilon)\cong \Bbb{C}^{d^2-1} -- and construct an explicit basis for the corresponding second cohomology group for Od+O_d^+ (whose dimension was known earlier thanks to the work of Collins, H\"artel and Thom).

Keywords

Cite

@article{arxiv.1711.02755,
  title  = {L\'evy-Khintchine decompositions for generating functionals on algebras associated to universal compact quantum groups},
  author = {Biswarup Das and Uwe Franz and Anna Kula and Adam Skalski},
  journal= {arXiv preprint arXiv:1711.02755},
  year   = {2018}
}

Comments

30 pages, v4 has a slightly modified title and contains several presentational changes (main mathematical contents remain unchanged). The paper will appear in Infinite Dimensional Analysis, Quantum Probability and Related Topics

R2 v1 2026-06-22T22:39:30.155Z