697 research outputs found
Unitarizing non-Minimal Inflation via a Linear Contribution to the Frame Function
We show that non-minimal inflation, based on the phi^4 potential, may be
rendered unitarity conserving and compatible with the Planck results for
4.6x10^(-3)<~r21=c2R/c1R^2<~1, if we introduce a linear contribution (c1R phi)
to the frame function which takes the form fR=1+c1R phi+c2R phi^2.
Supersymmetrization of this model can be achieved by considering two gauge
singlet superfields and combining a linear-quadratic superpotential term, with
a class of logarithmic or semi-logarithmic Kaehler potentials with prefactor
for the logarithms including the inflaton field -(2n+3) or -2(n+1) where
-0.01<~ n<~0.013.Comment: Published Version. arXiv admin note: text overlap with
arXiv:1807.0115
F-Term Hybrid Inflation Followed by a Peccei-Quinn Phase Transition
We consider a cosmological set-up, based on renormalizable superpotential
terms, in which a superheavy scale F-term hybrid inflation is followed by a
Peccei-Quinn phase transition, resolving the strong CP and mu problems of the
minimal supersymmetric standard model. We show that the field which triggers
the Peccei-Quinn phase transition can remain after inflation well above the
Peccei-Quinn scale thanks to (i) its participation in the supergravity and
logarithmic corrections during the inflationary stage and (ii) the high reheat
temperature after the same period. As a consequence, its presence influences
drastically the inflationary dynamics and the universe suffers a second period
of reheating after the Peccei-Quinn phase transition. Confronting our
inflationary predictions with the current observational data, we find that, for
about the central value of the spectral index, the grand unification scale can
be identified with its supersymmetric value for the relevant coupling constant
\kappa=0.002 and, more or less, natural values, +/-(0.01-0.1), for the
remaining parameters. On the other hand, the final reheat temeperature after
the Peccei-Quinn phase transition turns out to be low enough so as the
gravitino problem is avoided.Comment: 15 pages including 8 figures, version published in Phys. Rev.
Gravitational Waves, mu Term & Leptogenesis from B-L Higgs Inflation in Supergravity
We consider a renormalizable extension of the minimal supersymmetric standard
model endowed by an R and a gauged B - L symmetry. The model incorporates
chaotic inflation driven by a quartic potential, associated with the Higgs
field which leads to a spontaneous breaking of U(1)B-L, and yields possibly
detectable gravitational waves. We employ quadratic Kahler potentials with a
prominent shift-symmetric part proportional to c- and a tiny violation,
proportional to c+, included in a logarithm with prefactor -N<0. It also offers
an explanation of mu term of the MSSM provided that one related parameter in
the superpotential is somewhat small. Baryogenesis occurs via non-thermal
leptogenesis which is realized by the inflaton's decay to the lightest or
next-to-lightest right-handed neutrino with masses lower than 1.8x10^13 GeV.
Our scenario can be confronted with the current data on the inflationary
observables, the baryon asymmetry of the universe, the gravitino limit on the
reheating temperature and the data on the neutrino oscillation parameters, for
0.012<=c+/c-<1/N and gravitino as light as 1 TeV.Comment: Published version. arXiv admin note: text overlap with
arXiv:1312.362
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