PT Journal
AU Lazaries, G
   Pallis, C
TI Shift symmetry and Higgs inflation in supergravity with observable gravitational waves
SO Journal of High Energy Physics
JI J. High Energy Phys.
PY 2015
BP 114
EP 28pp
VL 11
IS 11
DI 10.1007/JHEP11(2015)114
LA English
DE Cosmology of Theories beyond the SM; Supergravity Models; Supersymmetric Effective Theories
AB We demonstrate how to realize within supergravity a novel chaotic-type inflationary scenario driven by the radial parts of a conjugate pair of Higgs superfields causing the spontaneous breaking of a grand unified gauge symmetry at a scale assuming the value of the supersymmetric grand unification scale. The superpotential is uniquely determined at the renormalizable level by the gauge symmetry and a continuous R symmetry. We select two types of Kahler potentials, which respect these symmetries as well as an approximate shift symmetry. In particular, they include in a logarithm a dominant shift-symmetric term proportional to a parameter c_ together with a small term violating this symmetry and characterized by a parameter c(+). In both cases, imposing a lower bound on c_, inflation can be attained with subplanckian values of the original inflaton, while the corresponding effective theory respects perturbative unitarity for r +/- = c(+)/c_ <= 1. These inflationary models do not lead to overproduction of cosmic defects, are largely independent of the one-loop radiative corrections and accommodate, for natural values of r +/-, observable gravitational waves consistently with all the current observational data. The inflaton mass is mostly confined in the range (3.7 – 8.1) x 10(10) GeV.
ER