Quaternionic Contact Manifolds with a Closed Fundamental 4-form
نویسنده
چکیده
We define a global horizontal 4-form on a quaternionic contact manifold and show that it is closed if and only if the torsion of the Biquard connection vanishes provided the dimension is grater than seven. This condition characterizes quaternionic contact structures which are locally qc homothetic to 3-sasakian.
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