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arXiv · 1608.02942

Positivity of Curvature-Squared Corrections in Gravity

Clifford Cheung·Grant N. Remmen
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Abstract

We study the Gauss-Bonnet (GB) term as the leading higher-curvature correction to pure Einstein gravity. Assuming a tree-level ultraviolet completion free of ghosts or tachyons, we prove that the GB term has a nonnegative coefficient in dimensions greater than four. Our result follows from unitarity of the spectral representation for a general ultraviolet completion of the GB term.

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Clifford Cheung, Grant N. Remmen. 2017-02-01. Positivity of Curvature-Squared Corrections in Gravity. https://doi.org/10.1103/physrevlett.118.051601

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