Galilean symmetry in the effective theory of inflation: new shapes of non-Gaussianity
- 1 February 2011
- journal article
- Published by IOP Publishing in Journal of Cosmology and Astroparticle Physics
- Vol. 2011 (02), 006
- https://doi.org/10.1088/1475-7516/2011/02/006
Abstract
We study the consequences of imposing an approximate Galilean symmetry on the Effective Theory of Inflation, the theory of small perturbations around the inflationary background. This approach allows us to study the effect of operators with two derivatives on each field, which can be the leading interactions due to non-renormalization properties of the Galilean Lagrangian. In this case cubic non-Gaussianities are given by three independent operators, containing up to six derivatives, two with a shape close to equilateral and one peaking on flattened isosceles triangles. The four-point function is larger than in models with small speed of sound and potentially observable with the Planck satellite.Keywords
Other Versions
This publication has 29 references indexed in Scilit:
- Galileon inflationJournal of Cosmology and Astroparticle Physics, 2011
- Inflation Driven by the Galileon FieldPhysical Review Letters, 2010
- Primordial non-Gaussianity from the DBI GalileonsPhysical Review D, 2010
- Galileon as a local modification of gravityPhysical Review D, 2009
- The effective field theory of inflationJournal of High Energy Physics, 2008
- Observational signatures and non-Gaussianities of general single-field inflationJournal of Cosmology and Astroparticle Physics, 2007
- Starting the Universe: stable violation of the null energy condition and non-standard cosmologiesJournal of High Energy Physics, 2006
- DBI in the sky: Non-Gaussianity from inflation with a speed limitPhysical Review D, 2004
- Stability of flat space, semiclassical gravity, and higher derivativesPhysical Review D, 1991
- Higher-derivative Lagrangians, nonlocality, problems, and solutionsPhysical Review D, 1990