409,626 research outputs found
Replica analysis of the generalized p-spin interaction glass model
We investigate stability of replica symmetry breaking solutions in
generalized -spin models. It is shown that the kind of the transition to the
one-step replica symmetry breaking state depends not only on the presence or
absence of the reflection symmetry of the generalized "spin"-operators
but on the number of interacting operators and their individual
characteristics.Comment: 14 pages, 1 figur
Suppressing Proton Decay by Cancellation in S_4 Flavor Symmetric Extra U(1) Model
We consider proton stability based on E_6 inspired extra U(1) model with S_4
flavor symmetry. In this model, a long life time of proton is realized by the
flavor symmetry. One of the interesting effects of flavor symmetry is that the
proton decay widths of p -> mu^+, X are suppressed by cancellation. This
suppression mechanism is important in the case that Yukawa coupling constants
are hierarchical. Our model predicts p -> e^+, K^0 has larger decay width than
that of p -> mu^+, K^0.Comment: 16 pages, 5 tables, and 1 figure; version accepted for publication in
Progress of Theoretical Physics. arXiv admin note: text overlap with
arXiv:1111.109
On thin-shell wormholes evolving in flat FRW spacetimes
We analize the stability of a class of thin-shell wormholes with spherical
symmetry evolving in flat FRW spacetimes. The wormholes considered here are
supported at the throat by a perfect fluid with equation of state
and have a physical radius equal to , where is a
time-dependent function describing the dynamics of the throat and is the
background scale factor. The study of wormhole stability is done by means of
the stability analysis of dynamic systems.Comment: 8 pages; to appear in MPL
Phase structures of the black D-D-brane system in various ensembles II: electrical and thermodynamic stability
By incorporating the electrical stability condition into the discussion, we
continue the study on the thermodynamic phase structures of the D-D
black brane in GG, GC, CG, CC ensembles defined in our previous paper
arXiv:1502.00261. We find that including the electrical stability conditions in
addition to the thermal stability conditions does not modify the phase
structure of the GG ensemble but puts more constraints on the parameter space
where black branes can stably exist in GC, CG, CC ensembles. In particular, the
van der Waals-like phase structure which was supposed to be present in these
ensembles when only thermal stability condition is considered would no longer
be visible, since the phase of the small black brane is unstable under
electrical fluctuations. However, the symmetry of the phase structure by
interchanging the two kinds of brane charges and potentials is still preserved,
which is argued to be the result of T-duality.Comment: 34 pages, 17 figure
Z_p scalar dark matter from multi-Higgs-doublet models
In many models, stability of dark matter particles is protected by a
conserved Z_2 quantum number. However dark matter can be stabilized by other
discrete symmetry groups, and examples of such models with custom-tailored
field content have been proposed. Here we show that electroweak symmetry
breaking models with N Higgs doublets can readily accommodate scalar dark
matter candidates stabilized by groups Z_p with any , leading to
a variety of kinds of microscopic dynamics in the dark sector. We give examples
in which semi-annihilation or multiple semi-annihilation processes are allowed
or forbidden, which can be especially interesting in the case of asymmetric
dark matter.Comment: 10 page
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