100 research outputs found
Observable Gravity Waves from Supersymmetric Hybrid Inflation II
It is shown that a tensor-to-scalar ratio close to r = 0.03, which can be
observed by Planck, is realized in supersymmetric hybrid inflation models with
TeV-scale soft supersymmetry breaking terms. This extends our previous
analysis, which also found r <~ 0.03 but employed intermediate scale soft
terms. Other cosmological observables such as the scalar spectral index are in
good agreement with the WMAP data.Comment: 4 pages, 4 figure
Amelioration of Little Hierarchy Problem in SU(4)_c x SU(2)_L x SU(2)_R
The little hierarchy problem encountered in the constrained minimal
supersymmetric model (CMSSM) can be ameliorated in supersymmetric models based
on the gauge symmetry G_{422} \equiv SU(4)_c x SU(2)_L x SU(2)_R. The standard
assumption in CMSSM (and in SU(5) and SO(10)) of universal gaugino masses can
be relaxed in G_{422}, and this leads to a significant improvement in the
degree of fine tuning required to implement radiative electroweak breaking in
the presence of a characteristic supersymmetry breaking scale of around a TeV.
Examples of Higgs and sparticle mass spectra realized with 10% fine tuning are
presented.Comment: 14 pages, 5 figures, 2 table
Higgs Boson Mass, Sparticle Spectrum and Little Hierarchy Problem in Extended MSSM
We investigate the impact of TeV-scale matter belonging to complete
vectorlike multiplets of unified groups on the lightest Higgs boson in the
MSSM. We find that consistent with perturbative unification and electroweak
precision data the mass m_h can be as large as 160 GeV. These extended MSSM
models can also render the little hierarchy problem less severe, but only for
lower values of m_h < 125 GeV. We present estimates for the sparticle mass
spectrum in these models.Comment: 27 pages, 14 figure
Red Spectral Tilt and Observable Gravity Waves in Shifted Hybrid Inflation
We consider supersymmetric shifted hybrid inflation models with a red tilted
scalar spectral index n_s in agreement with the WMAP 7-yr central value. If
non-minimal supergravity corrections are included, these models can also
support a tensor-to-scalar ratio as large as r = 0.02, which may be observable
by the Planck Satellite. In contrast to the standard supersymmetric hybrid
inflation scenario, topological defects produced via gauge symmetry breaking
are inflated away in the shifted version of the theory.Comment: 22 pages, 4 figures, and 1 tabl
Higgs Inflation, Quantum Smearing and the Tensor to Scalar Ratio
In cosmic inflation driven by a scalar gauge singlet field with a tree level
Higgs potential, the scalar to tensor ratio r is estimated to be larger than
0.036, provided the scalar spectral index n_s >= 0.96. We discuss quantum
smearing of these predictions arising from the inflaton couplings to other
particles such as GUT scalars, and show that these corrections can
significantly decrease r. However, for n_s >= 0.96, we obtain r >= 0.02 which
can be tested by the Planck satellite.Comment: 10 pages, 3 figures and 3 table
Supersymmetric And Smooth Hybrid Inflation In The Light Of WMAP3
In their minimal form both supersymmetric and smooth hybrid inflation yield a
scalar spectral index n_s close to 0.98, to be contrasted with the result
n_s=0.951+0.015-0.019 from WMAP3. To realize better agreement, following
hep-ph/0604198, we extend the parameter space of these models by employing a
non-minimal Kaehler potential. We also discuss non-thermal leptogenesis by
inflaton decay and obtain new bounds in these models on the reheat temperature
to explain the observed baryon asymmetry.Comment: 21 pages, 12 figures, revtex4. v2: minor revisions, additional
references, to appear in PR
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