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arXiv · 1607.01784

On the curious spectrum of duality invariant higher-derivative gravity

Olaf Hohm·Usman Naseer·Barton Zwiebach
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Abstract

We analyze the spectrum of the exactly duality and gauge invariant higher-derivative double field theory. While this theory is based on a chiral CFT and does not correspond to a standard string theory, our analysis illuminates a number of issues central in string theory. The full quadratic action is rewritten as a two-derivative theory with additional fields. This allows for a simple analysis of the spectrum, which contains two massive spin-2 ghosts and massive scalars, in addition to the massless fields. Moreover, in this formulation, the massless or tensionless limit $\alpha'\rightarrow \infty$ is non-singular and leads to an enhanced gauge symmetry. We show that the massive modes can be integrated out exactly at the quadratic level, leading to an infinite series of higher-derivative corrections. Finally, we present a ghost-free massive extension of linearized double field theory, which employs a novel mass term for the dilaton and metric.

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Olaf Hohm, Usman Naseer, Barton Zwiebach. 2016-07-06. On the curious spectrum of duality invariant higher-derivative gravity. https://doi.org/10.1007/jhep08(2016)173

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