An equation of Monge-Ampère type in conformal geometry, and four-manifolds of positive Ricci curvature
نویسندگان
چکیده
We formulate natural conformally invariant conditions on a 4-manifold for the existence of a metric whose Schouten tensor satisfies a quadratic inequality. This inequality implies that the eigenvalues of the Ricci tensor are positively pinched.
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