Non-gaussian inflationary shapes inG3theories beyond Horndeski

2014/07/31 by Matteo Fasiello, Sébastien Renaux-Petel · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Class (philosophy) #Cosmology and Gravitation Theories #Covariance #Curvature #Dispersion relation #General covariance #Order (exchange) #Quantum Chromodynamics and Particle Interactions #Relation (database) #astro-ph.CO #gr-qc #hep-th

paper · pdf · doi:10.1088/1475-7516/2014/10/037

17 pages. Analysis expanded and some references added

arxiv created 2014/09/03 · openalex publication_date 2014/10/15 · arxiv updated 2015/06/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

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 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.

Citations

• A formal introduction to Horndeski and Galileon theories and their generalizations
• Non-Gaussian inflationary perturbations from the dS/CFT correspondence
• Second-order scalar-tensor field equations in a four-dimensional space
• Observational signatures and non-Gaussianities of general single-field inflation
• The galileon as a local modification of gravity
• Generalized G-inflation: Inflation with the most general second-order field equations
• Galileon inflation

Cited by

• Nonsingular cosmological models with strong gravity in the past
• Multi-disformal invariance of non-linear primordial perturbations