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On the complex structure of symplectic quotients. (English) Zbl 1489.53101

Summary: Let \(K\) be a compact group. For a symplectic quotient \(M_{\lambda}\) of a compact Hamiltonian Kähler \(K\)-manifold, we show that the induced complex structure on \(M_{\lambda}\) is locally invariant when the parameter \(\lambda\) varies in \(\mathrm{Lie}(K)^{\ast}\). To prove such a result, we take two different approaches: (i) use the complex geometry properties of the symplectic implosion construction; (ii) investigate the variation of geometric invariant theory (GIT) quotients.

MSC:

53C55 Global differential geometry of Hermitian and Kählerian manifolds
53D20 Momentum maps; symplectic reduction
14L24 Geometric invariant theory

References:

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