For a space equipped with a -connection on a bundle (for some Lie group ) and for any point, the parallel transport of assigns to each curve in starting and ending at an element : the holonomy of along that curve.
The holonomy group of at is the subgroup of on these elements.
If is the Levi-Civita connection on a Riemannian manifold and the holonomy group is a proper subgroup of the special orthogonal group, one says that is a manifold of special holonomy .
holonomy group
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