English

Critical values of moment maps on quantizable manifolds

Symplectic Geometry 2007-11-05 v1

Abstract

Let MM be a quantizable symplectic manifold acted on by T=(S1)rT=(S^1)^r in a Hamiltonian fashion and JJ a moment map for this action. Suppose that the set MTM^{T} of fixed points is discrete and denote by αpjZr{\alpha}_{pj}\in{\mathbb Z}^r the weights of the isotropy representation at pp. By means of the αpj\alpha_{pj}'s we define a partition Q+{\mathcal Q}_+, Q{\mathcal Q}_- of MTM^T. (When r=1r=1, Q±{\mathcal Q}_{\pm} will be the set of fixed points such that the half of the Morse index of JJ at them is even (odd)). We prove the existence of a map π±:Q±Q\pi_{\pm}:{\mathcal Q}_{\pm}\to{\mathcal Q}_{\mp} such that J(q)J(π±(q))IJ(q)-J(\pi_{\pm}(q))\in I_{\mp}, for all qQ±q\in {\mathcal Q}_{\pm}, where I±I_{\pm} is the lattice generated by the αpj\alpha_{pj}'s with pQ±.p\in{\mathcal Q}_{\pm}. We define partition functions NpN_p similar to the ones of Kostant \cite{Gui} and we prove that pQ+Np(l)=pQNp(l)\sum_{p\in{\mathcal Q}_+}N_p(l)=\sum_{p\in{\mathcal Q}_-}N_p(l), for any lZrl\in{\mathbb Z}^r with l|l| sufficiently large.

Keywords

Cite

@article{arxiv.0711.0358,
  title  = {Critical values of moment maps on quantizable manifolds},
  author = {Andrés Viña},
  journal= {arXiv preprint arXiv:0711.0358},
  year   = {2007}
}

Comments

10 pages, comments are wellcome

R2 v1 2026-06-21T09:39:18.391Z