English

Generalized multi-Galileons, covariantized new terms, and the no-go theorem for non-singular cosmologies

High Energy Physics - Theory 2017-04-11 v2 Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology

Abstract

It has been pointed out that non-singular cosmological solutions in second-order scalar-tensor theories generically suffer from gradient instabilities. We extend this no-go result to second-order gravitational theories with an arbitrary number of interacting scalar fields. Our proof follows directly from the action of generalized multi-Galileons, and thus is different from and complementary to that based on the effective field theory approach. Several new terms for generalized multi-Galileons on a flat background were proposed recently. We find a covariant completion of them and confirm that they do not participate in the no-go argument.

Keywords

Cite

@article{arxiv.1701.02926,
  title  = {Generalized multi-Galileons, covariantized new terms, and the no-go theorem for non-singular cosmologies},
  author = {Shingo Akama and Tsutomu Kobayashi},
  journal= {arXiv preprint arXiv:1701.02926},
  year   = {2017}
}

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7 pages