229 research outputs found
Particle physics and cosmology with high-scale SUSY breaking in five-dimensional supergravity models
We discuss a high-scale SUSY breaking scenario with the wino dark matter in
the five-dimensional supergravity model on . The extra U(1) symmetries
broken by the orbifold projection control the flavor structure of soft
SUSY-breaking parameters as well as the Yukawa couplings, and a scalar
component of the one of moduli multiplets, which arise from extra-dimensional
components of the U(1) vector multiplets, induces the slow-roll inflation.
Because of the supersymmetric moduli stabilization as well as the moduli
inflation, it is found that the correct dark matter relic abundance is
non-thermally generated by the gravitino decaying into the wino.Comment: 19 pages, 1 figure, typos corrected and references adde
On the Flux Vacua in F-theory Compactifications
We study moduli stabilization of the F-theory compactified on an elliptically
fibered Calabi-Yau fourfold. Our setup is based on the mirror symmetry
framework including brane deformations. The complex structure moduli dependence
of the resulting 4D N=1 effective theory is determined by the associated
fourfold period integrals. By turning on appropriate G-fluxes, we explicitly
demonstrate that all the complex structure moduli fields can be stabilized
around the large complex structure point of the F-theory fourfold.Comment: 5 pages, v2: published versio
heterotic standard model vacua in general Calabi-Yau compactifications
We study a direct flux breaking scenario in heterotic string theory
on general Calabi-Yau threefolds. The direct flux breaking, corresponding to
hypercharge flux breaking in the F-theory context, allows us to derive the
Standard Model in general Calabi-Yau compactifications. We present a general
formula leading to the three generations of quarks and leptons and no chiral
exotics in a background-independent way. As a concrete example, we show the
three-generation model on a complete intersection Calabi-Yau threefold.Comment: 22 page
Natural inflation with and without modulations in type IIB string theory
We propose a mechanism for the natural inflation with and without modulation
in the framework of type IIB string theory on toroidal orientifold or orbifold.
We explicitly construct the stabilization potential of complex structure,
dilaton and K\"ahler moduli, where one of the imaginary component of complex
structure moduli becomes light which is identified as the inflaton. The
inflaton potential is generated by the gaugino-condensation term which receives
the one-loop threshold corrections determined by the field value of complex
structure moduli and the axion decay constant of inflaton is enhanced by the
inverse of one-loop factor. We also find the threshold corrections can also
induce the modulations to the original scalar potential for the natural
inflation. Depending on these modulations, we can predict several sizes of
tensor-to-scalar ratio as well as the other cosmological observables reported
by WMAP, Planck and/or BICEP2 collaborations.Comment: 18 pages, 4 figures, Typos corrected, references and comments adde
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