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arXiv · 1311.3828

Noether Identities and Gauge-Fixing the Action for Cosmological Perturbations

Macarena Lagos·Máximo Bañados·Pedro G. Ferreira·Sebastián García-Sáenz
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Abstract

We propose and develop a general algorithm for finding the action for cosmological perturbations which rivals the conventional, gauge-invariant approach and can be applied to theories with more than one metric. We then apply it to a particular case of bigravity, focusing on the Eddington- inspired Born-Infeld theory, and show that we can obtain a nearly scale-invariant power spectrum for both scalar and tensor primordial quantum perturbations. Unfortunately, in the case of the minimal Eddington-inspired Born-Infeld theory, we find that the tensor-to-scalar ratio of perturbations is unacceptably large. We discuss the applicability of our general method and the possibility of resurrecting the specific theory we have looked at.

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Macarena Lagos, Máximo Bañados, Pedro G. Ferreira, Sebastián García-Sáenz. 2013-11-15. Noether Identities and Gauge-Fixing the Action for Cosmological Perturbations. https://doi.org/10.1103/physrevd.89.024034

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