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Canonical Sasakian Metrics

Charles P. Boyer·Krzysztof Galicki·Santiago R. Simanca
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Abstract

Let $M$ be a closed manifold of Sasaki type. A polarization of $M$ is defined by a Reeb vector field, and for one such, we consider the set of all Sasakian metrics compatible with it. On this space, we study the functional given by the squared $L^2$-norm of the scalar curvature. We prove that its critical points, or canonical representatives of the polarization, are Sasakian metrics that are transversally extremal. We define a Sasaki-Futaki invariant of the polarization, and show that it obstructs the existence of constant scalar curvature representatives. For a fixed CR structure of Sasaki type, we define the Sasaki cone of structures compatible with this underlying CR structure, and prove that the set of polarizations in it that admit a canonical representative is open.

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Charles P. Boyer, Krzysztof Galicki, Santiago R. Simanca. 2007-03-13. Canonical Sasakian Metrics. https://doi.org/10.1007/s00220-008-0429-1

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