3-Sasakian manifolds, 3-cosymplectic manifolds and Darboux theorem

CAPPELLETTI MONTANO, BENIAMINO;DE NICOLA A.

2007-01-01

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Abstract

We present a compared analysis of some properties of 3-Sasakian and 3-cosymplectic manifolds. We construct a canonical connection on an almost 3-contact metric manifold which generalises the Tanaka–Webster connection of a contact metric manifold and we use this connection to show that a 3-Sasakian manifold does not admit any Darboux-like coordinate system. Moreover, we prove that any 3-cosymplectic manifold is Ricci-flat and admits a Darboux coordinate system if and only if it is flat.