10,052 research outputs found
Domain walls in gapped graphene
The electronic properties of a particular class of domain walls in gapped
graphene are investigated. We show that they can support mid-gap states which
are localized in the vicinity of the domain wall and propagate along its
length. With a finite density of domain walls, these states can alter the
electronic properties of gapped graphene significantly. If the mid-gap band is
partially filled,the domain wall can behave like a one-dimensional metal
embedded in a semi-conductor, and could potentially be used as a single-channel
quantum wire.Comment: 4 pgs. revte
Symplectic Geometry on Quantum Plane
A study of symplectic forms associated with two dimensional quantum planes
and the quantum sphere in a three dimensional orthogonal quantum plane is
provided. The associated Hamiltonian vector fields and Poissonian algebraic
relations are made explicit.Comment: 12 pages, Late
Gravitino dark matter from gluino late decay in split supersymmetry
In split-supersymmetry (split-SUSY), gluino is a metastable particle and thus
can freeze out in the early universe. The late decay of such a long-life gluino
into the lightest supersymmetric particle (LSP) may provide much of the cosmic
dark matter content. In this work, assuming the LSP is gravitino produced from
the late decay of the metastable gluino, we examine the WMAP dark matter
constraints on the gluino mass. We find that to provide the full abundance of
dark matter, the gluino must be heavier than about 14 TeV and thus not
accessible at the CERN Large Hadron Collider (LHC).Comment: discussions added (version in PRD
BRST Structures and Symplectic Geometry on a Class of Supermanifolds
By investigating the symplectic geometry and geometric quantization on a
class of supermanifolds, we exhibit BRST structures for a certain kind of
algebras. We discuss the undeformed and q-deformed cases in the classical as
well as in the quantum cases.Comment: 14 pages, Late
Steady Euler Flows with Large Vorticity and Characteristic Discontinuities in Arbitrary Infinitely Long Nozzles
We establish the existence and uniqueness of smooth solutions with large
vorticity and weak solutions with vortex sheets/entropy waves for the steady
Euler equations for both compressible and incompressible fluids in arbitrary
infinitely long nozzles. We first develop a new approach to establish the
existence of smooth solutions without assumptions on the sign of the second
derivatives of the horizontal velocity, or the Bernoulli and entropy functions,
at the inlet for the smooth case. Then the existence for the smooth case can be
applied to construct approximate solutions to establish the existence of weak
solutions with vortex sheets/entropy waves by nonlinear arguments. This is the
first result on the global existence of solutions of the multidimensional
steady compressible full Euler equations with free boundaries, which are not
necessarily small perturbations of piecewise constant background solutions. The
subsonic-sonic limit of the solutions is also shown. Finally, through the
incompressible limit, we establish the existence and uniqueness of
incompressible Euler flows in arbitrary infinitely long nozzles for both the
smooth solutions with large vorticity and the weak solutions with vortex
sheets. The methods and techniques developed here will be useful for solving
other problems involving similar difficulties.Comment: 43 pages; 2 figures; To be published in Advances in Mathematics
(2019
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