Non-gaussian inflationary shapes in G{sup 3} theories beyond Horndeski

Journal Article · Wed Oct 01 00:00:00 EDT 2014 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2014/10/037· OSTI ID:22375822

Fasiello, Matteo ^[1]; Renaux-Petel, Sébastien ^[2]

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1. CERCA and Department of Physics, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106 (United States)
2. Laboratoire de Physique Théorique et Hautes Energies, Université Pierre and Marie Curie—Paris VI, CNRS-UMR 7589, 4 place Jussieu, 75252 Paris (France)

We consider the possible signatures of a recently introduced class of healthy theories beyond Horndeski models on higher-order correlators of the inflationary curvature fluctuation. Despite the apparent large number and complexity of the cubic interactions, we show that the leading-order bispectrum generated by the Generalized Horndeski (also called G{sup 3}) interactions can be reduced to a linear combination of two well known k-inflationary shapes. We conjecture that said behavior is not an accident of the cubic order but a consequence dictated by the requirements on the absence of Ostrogradski instability, the general covariance and the linear dispersion relation in these theories.

• OSTI ID: 22375822
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2014, Issue 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCIDENTS
DISPERSION RELATIONS
FLUCTUATIONS
INSTABILITY
INTERACTIONS
SHAPE