TY - JOUR
T1 - Galilean symmetry in the effective theory of inflation
T2 - New shapes of non-Gaussianity
AU - Creminelli, Paolo
AU - D'Amico, Guido
AU - Musso, Marcello
AU - Norẽa, Jorge
AU - Trincherini, Enrico
PY - 2011/2
Y1 - 2011/2
N2 - 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.
AB - 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.
KW - inflation
KW - modified gravity
KW - non-gaussianity
UR - http://www.scopus.com/inward/record.url?scp=79952576619&partnerID=8YFLogxK
U2 - 10.1088/1475-7516/2011/02/006
DO - 10.1088/1475-7516/2011/02/006
M3 - Article
AN - SCOPUS:79952576619
VL - 2011
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
SN - 1475-7516
IS - 2
M1 - 006
ER -