E. Costa

most citedA modified Yamabe invariant and a Hopf conjecture

1 citations · 1 across the 3 of their papers we have counts for

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math.DG2015

Compact 4-manifolds with harmonic Weyl tensor and nonnegative biorthogonal curvature

Ezio Araujo Costa

In this note we classify compact 4-manifolds with harmonic Weyl tensor and nonnegative biorthogonal curvature

math.DG2012

The scalar curvature and the biorthogonal curvature: A pinching problem

Ezio Araujo Costa

The famous pinching problem says that on a compact simply connected $n$ -manifold if its sectional curvature satisfies $K_{min} > (1/4) K_{ma x} > 0$ , then the manifold is homeomorphi…

math.DG2012★ 1 cited

A modified Yamabe invariant and a Hopf conjecture

Ezio Araujo Costa

In this paper we define the bi-orthogonal sectional curvature and we present two modified Yamabe invariants for compact 4-dimensional manifolds. In particular we obtained a relatio…