English

Group valued moment maps for even and odd simple $G$-modules

Representation Theory 2026-04-01 v2 Symplectic Geometry

Abstract

Let GG be a complex simple Lie group, and g\mathfrak{g} its Lie algebra. It is well known that a finite-dimensional GG-module VV carrying a nondegenerate invariant bilinear form gives rise to a Hamiltonian Poisson space with a quadratic moment map μ\mu. We show that under condition Homg(3V,S3V)=0\mathrm{Hom}_{\mathfrak{g}}({\textstyle{\bigwedge}}^3 V, S^3V)=0 this space can be viewed as a quasi-Poisson space with the same bivector, and with the group valued moment map Φ=expμ\Phi = \exp \circ \mu. Furthermore, we show that by modifying the bivector by the standard rr-matrix for g\mathfrak{g} one obtains a space with a Poisson action of the Poisson-Lie group~GG, and with the moment map in the sense of Lu taking values in the dual Poisson-Lie group~GG^\ast.

Keywords

Cite

@article{arxiv.2507.19434,
  title  = {Group valued moment maps for even and odd simple $G$-modules},
  author = {Anton Alekseev and Andrey Krutov},
  journal= {arXiv preprint arXiv:2507.19434},
  year   = {2026}
}

Comments

20 pages

R2 v1 2026-07-01T04:19:09.878Z