English

Deformations of quasi-Hamiltonian spaces

Symplectic Geometry 2026-04-01 v2 Differential Geometry

Abstract

We introduce a notion of deformations of quasi-Hamiltonian GG-spaces to Hamiltonian GG-spaces and provide several examples. In particular, we show that the double G×GG \times G of a Lie group, viewed as a quasi-Hamiltonian G×GG \times G-space, deforms smoothly to the cotangent bundle TGT^*G. Likewise, any conjugacy class of GG sufficiently close to the identity deforms to a coadjoint orbit. We further show that the moduli space of flat GG-connections on a compact oriented surface of genus gg with r+1r+1 boundary components deforms to TGr+gT^*G^{r+g}.

Keywords

Cite

@article{arxiv.2505.16689,
  title  = {Deformations of quasi-Hamiltonian spaces},
  author = {Jean-Philippe Burelle and Mohamed Moussadek Maiza and Maxence Mayrand},
  journal= {arXiv preprint arXiv:2505.16689},
  year   = {2026}
}

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8 pages