83 research outputs found
Group manifold approach to higher spin theory
We consider the group manifold approach to higher spin theory. The deformed
local higher spin transformation is realized as the diffeomorphism
transformation in the group manifold . With the suitable rheonomy
condition and the torsion constraint imposed, the unfolded equation can be
obtained from the Bianchi identity, by solving which, fields in
are determined by the multiplet at one point, or equivalently, by
in . Although the
space is extended to to get the geometrical formulation, the
dynamical degrees of freedom are still in . The equations of
motion for are obtained by plugging the rheonomy
condition into the Bianchi identity. The proper rheonomy condition allowing for
the maximum on-shell degrees of freedom is given by Vasiliev equation. We also
discuss the theory with the global higher spin symmetry, which is in parallel
with the WZ model in supersymmetry.Comment: 35 pages,v2: revised version, v3: 38 pages, improved discussion on
global HS symmetry, clarifications added in appendix B, journal versio
U-duality transformation of membrane on revisited
The problem with the U-duality transformation of membrane on is
recently addressed in [arXiv:1509.02915 [hep-th]]. We will consider the
U-duality transformation rule of membrane on . It turns out that
winding modes on should be taken into account, since the duality
transformation may bring the membrane configuration without winding modes into
the one with winding modes. With the winding modes added, the membrane
worldvolume theory in lightcone gauge is equivalent to the dimensional
super-Yang-Mills (SYM) theory in , which has and symmetries for and , respectively. The
transformation can be realized classically, making the
on-shell field configurations transformed into each other. However, the
symmetry may only be realized at the quantum level, since the
classical SYM field configurations cannot form the representation of
.Comment: 19 pages; v2: 20 pages, reference corrected, extended discussion in
section 5, journal versio
The Minimal GUT with Inflaton and Dark Matter Unification
Giving up the solutions to the fine-tuning problems, we propose the
non-supersymmetric flipped model based on the minimal
particle content principle, which can be constructed from the four-dimensional
models, five-dimensional orbifold models, and local F-theory
models. To achieve gauge coupling unification, we introduce one pair
of vector-like fermions, which form complete
representation. Proton lifetime is around years, neutrino
masses and mixing can be explained via seesaw mechanism, baryon asymmetry can
be generated via leptogenesis, and vacuum stability problem can be solved as
well. In particular, we propose that inflaton and dark matter particle can be
unified to a real scalar field with symmetry, which is not an axion and
does not have the non-minimal coupling to gravity. Such kind of scenarios can
be applied to the generic scalar dark matter models. Also, we find that the
vector-like particle corrections to the masses can be about 6.6%, while
their corrections to the and masses are negligible.Comment: 5 pages, 4 figures;V2: published versio
General No-Scale Supergravity: An - Tale
We study the grand unification model flipped with additional
vector-like particle multiplets, or - for short, in the
framework of General No-Scale Supergravity. In our analysis we allow the
supersymmetry (SUSY) breaking soft terms to be generically non-zero, thereby
extending the phenomenologically viable parameter space beyond the highly
constrained one-parameter version of -. In this initial
inquiry, the mSUGRA/CMSSM SUSY breaking terms are implemented. We find this
easing away from the vanishing SUSY breaking terms enables a more broad mass
range of vector-like particles, dubbed flippons, including flippons less than 1
TeV that could presently be observed at the LHC2, as well as a lighter gluino
mass and SUSY spectrum overall. This presents heightened odds that the General
No-Scale - viable parameter space can be probed at the LHC2.
The phenomenology comprises both bino and higgsino dark matter, including a
Higgs funnel region. Particle states emerging from the SUSY cascade decays are
presented to experimentally distinguish amongst the diverse phenomenological
regions.Comment: 8 pages, 4 figures, 4 tables; Version accepted for publication in
Physics Letters
Supergravity inflation on a brane
We discuss supergravity inflation in braneworld cosmology for the class of
potentials with .
These minimal SUGRA models evade the problem due to a broken shift
symmetry and can easily accommodate the observational constraints. Models with
smaller are preferred while models with larger are out of the
region. Remarkably, the field excursions required for -foldings stay
sub-planckian .Comment: 10 pages, 4 figure
Decadal variation of prediction skill for Indian Ocean dipole over the past century
Indian Ocean dipole (IOD) is one of the dominant modes of interannual variability in the Indian Ocean, which has global climate impacts and thus is one of the key targets of seasonal predictions. In this study, based on a century-long seasonal hindcast experiment from the Coupled Seasonal Forecasts of the 20th century (CSF-20C), we show that the prediction skill for IOD exhibits remarkable decadal variations, with low skill in the early-to-mid 20th century but high skill in the second half of the 20th century. The decadal variations of prediction skills for IOD are caused by two factors. The first is associated with the decadal variation of the ENSO-IOD relationship. Although individual members of the predictions can simulate the variation of the ENSO-IOD relationship, with amplitude close to that in the observation, the feature is greatly suppressed in the ensemble mean due to the asynchrony of variation phases among individual members. In the ensemble mean, the IOD evolution shows an unrealistic stable and high correlation with ENSO evolution. This causes the prediction to have much higher skill for those periods during which IOD is accompanied by ENSO in the observation. The second factor is associated with the decadal variation of IOD predictability in the prediction system. In the prediction system, the decadal variation of IOD signal strength closely follows that of ENSO signal strength. Meanwhile, the IOD noise strength shows variations opposite to the IOD signal strength. As a result, the signal-to-noise ratio greatly increases in the second half of the 20th century due to the enhancement of the ENSO signal strength, which represents the increase of IOD predictability in the prediction system
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