Hyperkähler quotient

In mathematics, the hyperkähler quotient of a hyperkähler manifold acted on by a group G is the quotient of a fiber of the hyperkähler moment map M→R³⊗g* over a G-fixed point (or more generally a G-orbit) by the action of G. It was introduced by N. J. Hitchin, A. Karlhede, and U. Lindström et al. (1987). It is a hyperkähler analogue of the Kähler quotient.