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Second Variation of the "Total Scalar Curvature" on Contact Manifolds

Published online by Cambridge University Press:  20 November 2018

D. E. Blair
Affiliation:
Department of Mathematics, Michigan State University East Lansing, Michigan 48824 U.S.A.
D. Perrone
Affiliation:
Dipartimento di Matematica, Eacoltá di Scienze, Universitá Degli Studi di Lecce, Via Arnesano, 73100 Lecce, Italy
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Abstract

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Let M2n+1 be a compact contact manifold and 𝓐 the set of associated metrics. Using the scalar curvature R and the *-scalar curvature R*, in [5] we defined the "total scalar curvature", by and showed that the critical points of I(g) on 𝓐 are the K-contact metrics, i.e. metrics for which the characteristic vector field is Killing. In this paper we compute the second variation of I(g) and prove that the index of I(g) and of —I(g) are both positive at each critical point. As an application we show that the classical total scalar curvature A(g) = ∫M R dVg restricted to 𝓐 cannot have a local minimum at any Sasakian metric.

Keywords

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1995

References

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