The main contribution of this manuscript is a local
normal form for Hamiltonian actions of Poisson–Lie groups
on a symplectic manifold
equipped with an
-valued
moment map, where
is the
dual Poisson–Lie group of
.
Our proof uses the delinearization theorem of Alekseev which relates a classical Hamiltonian
action of
with
a
-valued
moment map to a Hamiltonian action with an
-valued
moment map, via a deformation of symplectic structures. We obtain our main
result by proving a “delinearization commutes with symplectic quotients”
theorem which is also of independent interest and then putting this together
with the local normal form theorem for classical Hamiltonian actions with
-valued
moment maps. A key ingredient for our main result is the delinearization
of the canonical
symplectic structure on
,
so we additionally take some steps toward explicit computations of
. In particular,
in the case
,
we obtain explicit formulas for the matrix coefficients of
with respect to a natural choice of coordinates on
.
Keywords
Hamiltonian actions, moment maps, Poisson–Lie groups, local
normal forms