85,317 research outputs found
Sneutrino Inflation with Asymmetric Dark Matter
The asymmetric dark matter scenario is known to give an interesting solution
for the cosmic coincidence problem between baryon and dark matter densities. In
the scenario, the dark matter asymmetry, which is translated to the dark matter
density in the present universe, is transferred from the B-L asymmetry
generated in the early universe. On the other hand, the generation of the B-L
asymmetry is simply assumed, though many mechanisms for the generation are
expected to be consistent with the scenario. We show that the generation of the
asymmetry in the sneutrino inflation scenario works similarly to the asymmetric
dark matter scenario, because the non-renormalizable operator which translates
the B-L asymmetry to the dark matter asymmetry is naturally obtained by
integrating right-handed neutrinos out. As a result, important issues
concerning cosmology (inflation, the mass density of dark matter, and the
baryon asymmetry of the universe) as well as neutrino masses and mixing have a
unified origin, namely, the right-handed neutrinos.Comment: 11 pages, 4 figures; v2: reference added, Fig. 3 changed and
explanation added; v3: version accepted for publication in PR
A Theory of Anomaly With Right-Handed Currents
We present an ultraviolet complete theory for the and anomaly
in terms of a low mass gauge boson of a class of left-right symmetric
models. These models, which are based on the gauge symmetry , utilize vector-like fermions to
generate quark and lepton masses via a universal seesaw mechanism. A parity
symmetric version as well as an asymmetric version are studied. A light sterile
neutrino emerges naturally in this setup, which allows for new decay modes of
-meson via right-handed currents. We show that these models can explain
and anomaly while being consistent with LHC and LEP data as
well as low energy flavor constraints arising from , mixing, etc., but only for a limited range
of the mass: for
parity asymmetric (symmetric) Yukawa sectors. The light sterile neutrinos
predicted by the model may be relevant for explaining the MiniBoone and LSND
neutrino oscillation results. The parity symmetric version of the model
provides a simple solution to the strong CP problem without relying on the
axion. It also predicts an isospin singlet top partner with a mass TeV.Comment: 43 pages, 7 figures, references added, model slightly modifie
A central limit theorem for the KPZ equation
We consider a two-parameter averaging-homogenization type elliptic problem together with the stochastic representation of the solution. A limit theorem is derived for the corresponding diffusion process and a precise description of the two-parameter limit behavior for the solution of the PDE is obtained.We consider the KPZ equation in one space dimension driven by a stationary centred space-time random field, which is sufficiently integrable and mixing, but not necessarily Gaussian. We show that, in the weakly asymmetric regime, the solution to this equation considered at a suitable large scale and in a suitable reference frame converges to the Hopf-Cole solution to the KPZ equation driven by space-time Gaussian white noise. While the limiting process depends only on the integrated variance of the driving field, the diverging constants appearing in the definition of the reference frame also depend on higher order moments
Interfacial layering in a three-component polymer system
We study theoretically the temporal evolution and the spatial structure of
the interface between two polymer melts involving three different species (A,
A* and B). The first melt is composed of two different polymer species A and A*
which are fairly indifferent to one another (Flory parameter chi_AA* ~ 0). The
second melt is made of a pure polymer B which is strongly attracted to species
A (chi_AB 0). We then show
that, due to these contradictory tendencies, interesting properties arise
during the evolution of the interface after the melts are put into contact: as
diffusion proceeds, the interface structures into several adjacent
"compartments", or layers, of differing chemical compositions, and in addition,
the central mixing layer grows in a very asymmetric fashion. Such unusual
behaviour might lead to interesting mechanical properties, and demonstrates on
a specific case the potential richness of multi-component polymer interfaces
(as compared to conventional two-component interfaces) for various
applications.Comment: Revised version, to appear in Macromolecule
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