Gelfand-Cetlin abelianizations of symplectic quotients
arXiv:2209.04978 · doi:10.2140/pjm.2024.333.253
Abstract
We show that generic symplectic quotients of a Hamiltonian -space by the action of a compact connected Lie group are also symplectic quotients of the same manifold by a compact torus. The torus action in question arises from certain integrable systems on , the dual of the Lie algebra of . Examples of such integrable systems include the Gelfand-Cetlin systems of Guillemin-Sternberg in the case of unitary and special orthogonal groups, and certain integrable systems constructed for all compact connected Lie groups by Hoffman-Lane. Our abelianization result holds for smooth quotients, and more generally for quotients which are stratified symplectic spaces in the sense of Sjamaar-Lerman.