Induced-gravity inflation in no-scale supergravity and beyond

• Published in: Journal of cosmology and astroparticle physics 2014-08, Vol.2014 (8), p.57-57
• Main Author: Pallis, C.
• Format: Article
• Language: English
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CHIRALITY; COSMOLOGICAL INFLATION; COUPLING; GRAVITATION; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; POTENTIALS; SUPERGRAVITY; SUPERSYMMETRY; UNITARITY
• ISSN: 1475-7516; 1475-7516
• DOI: 10.1088/1475-7516/2014/08/057

Supersymmetric versions of induced-gravity inflation are formulated within Supergravity (SUGRA) employing two gauge singlet chiral superfields. The proposed superpotential is uniquely determined by applying a continuous R and a discrete Z{sub n} symmetry. We select two types of logarithmic Kähler potentials, one associated with a no-scale-type SU(2,1)/SU(2)× U(1){sub R}×Z{sub n} Kähler manifold and one more generic. In both cases, imposing a lower bound on the parameter c{sub R} involved in the coupling between the inflaton and the Ricci scalar curvature — e.g. c{sub R}∼> 76, 105, 310 for n=2,3 and 6 respectively —, inflation can be attained even for subplanckian values of the inflaton while the corresponding effective theory respects the perturbative unitarity. In the case of no-scale SUGRA we show that, for every n, the inflationary observables remain unchanged and in agreement with the current data while the inflaton mass is predicted to be 3·10{sup 13} GeV. Beyond no-scale SUGRA the inflationary observables depend mildly on n and crucially on the coefficient involved in the fourth order term of the Kähler potential which mixes the inflaton with the accompanying non-inflaton field.