902 research outputs found
Anomalous magnetic and weak magnetic dipole moments of the lepton in the simplest little Higgs model
We obtain analytical expressions, both in terms of parametric integrals and
Passarino-Veltman scalar functions, for the one-loop contributions to the
anomalous weak magnetic dipole moment (AWMDM) of a charged lepton in the
framework of the simplest little Higgs model (SLHM). Our results are general
and can be useful to compute the weak properties of a charged lepton in other
extensions of the standard model (SM). As a by-product we obtain generic
contributions to the anomalous magnetic dipole moment (AMDM), which agree with
previous results. We then study numerically the potential contributions from
this model to the lepton AMDM and AWMDM for values of the parameter
space consistent with current experimental data. It is found that they depend
mainly on the energy scale at which the global symmetry is broken and the
parameter, whereas there is little sensitivity to a mild change in
the values of other parameters of the model. While the AMDM is of the
order of , the real (imaginary) part of its AWMDM is of the order of
(). These values seem to be out of the reach of the
expected experimental sensitivity of future experiments.Comment: 23 pages, 11 figures, new analysis and References adde
Complex Hybrid Inflation and Baryogenesis
We propose a hybrid inflation model with a complex waterfall field which
contains an interaction term that breaks the U(1) global symmetry associated to
the waterfall field charge. We show that the asymmetric evolution of the real
and imaginary parts of the complex field during the phase transition at the end
of inflation translates into a charge asymmetry. The latter strongly depends on
the vev of the waterfall field, which is well constrained by diverse
cosmological observations.Comment: 4 RevTex pages, no figures. Changes made in response to referee's
comments; matches version published in Phys.Rev.Let
On the dynamics of a quadratic scalar field potential
We review the attractor properties of the simplest chaotic model of
inflation, in which a minimally coupled scalar field is endowed with a
quadratic scalar potential. The equations of motion in a flat
Friedmann-Robertson-Walker universe are written as an autonomous system of
equations, and the solutions of physical interest appear as critical points.
This new formalism is then applied to the study of inflation dynamics, in which
we can go beyond the known slow-roll formalism of inflation.Comment: 14 pages, 6 eps figures, matches version to appear in IJMP
Newtonian Collapse of Scalar Field Dark Matter
In this letter, we develop a Newtonian approach to the collapse of galaxy
fluctuations of scalar field dark matter under initial conditions inferred from
simple assumptions. The full relativistic system, the so called
Einstein-Klein-Gordon, is reduced to the Schr\"odinger-Newton one in the weak
field limit. The scaling symmetries of the SN equations are exploited to track
the non-linear collapse of single scalar matter fluctuations. The results can
be applied to both real and complex scalar fields.Comment: 4 pages RevTex4 file, 4 eps figure
Triple unification of inflation, dark matter, and dark energy using a single field
We construct an explicit scenario whereby the same material driving inflation
in the early Universe can comprise dark matter in the present Universe, using a
simple quadratic potential. Following inflation and preheating, the density of
inflaton/dark matter particles is reduced to the observed level by a period of
thermal inflation, of a duration already invoked in the literature for other
reasons. Within the context of the string landscape, one can further argue for
a non-zero vacuum energy of this field, thus unifying inflation, dark matter
and dark energy into a single fundamental field.Comment: 5 pages RevTeX with 3 figures incorporate
Inflation, dark matter and dark energy in the string landscape
We consider the conditions needed to unify the description of dark matter,
dark energy and inflation in the context of the string landscape. We find that
incomplete decay of the inflaton field gives the possibility that a single
field is responsible for all three phenomena. By contrast, unifying dark matter
and dark energy into a single field, separate from the inflaton, appears rather
difficult.Comment: 4 pages RevTex4. Updated to include a toy model of reheating. Matches
version accepted by Phys Rev Let
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