34 research outputs found
Dimensional Reduction of a 6-dimensional Self-Dual Gauge Field Theory
A self-dual gauge field theory of the type introduced in refs. (5)(6) on a 6-dimensional manifold is subject to a dimensional reduction procedure to yield gauge-field-Higgs models in 4 and 3-dimensional manifolds. In the latter case, the magnetic field is defined
Goldstone models in D+1 dimensions, D=3,4,5, supporting stable and zero topological charge solutions
We study finite energy static solutions to a global symmetry breaking
Goldstone model described by an isovector scalar field in D+1 spacetime
dimensions. Both topologically stable multisolitons with arbitrary winding
numbers, and zero topological charge soliton--antisoliton solutions are
constructed numerically in D=3,4,5. We have explored the types of symmetries
the systems should be subjected to, for there to exist multisoliton and
soliton--antisoliton pairs in D=3,4,5,6. These findings are underpinned by
constructing numerical solutions in the examples. Subject to axial
symmetry, only multisolitons of all topological charges exist in even D, and in
odd D, only zero and unit topological charge solutions exist. Subjecting the
system to weaker than axial symmetries, results in the existence of all the
possibilities in all dimensions. Our findings apply also to finite 'energy'
solutions to Yang--Mills and Yang-Mills--Higgs systems, and in principle also
sigma models.Comment: 29 pages, 6 figure
Maxwell--Chern-Simons gauged non-relativistic O(3) model with self-dual vortices
A non-relativistic version of the 2+1 dimensional gauged Chern-Simons O(3)
sigma model, augmented by a Maxwell term, is presented and shown to support
topologically stable static self-dual vortices. Exactly like their counterparts
of the ungauged model, these vortices are shown to exhibit Hall behaviour in
their dynamics.Comment: 12 pages, LateX, to appear in Mod. Phys. Lett. 199
Yang--Mills sphalerons in all even spacetime dimensions , : =3,4
The classical solutions to higher dimensional Yang--Mills (YM) systems, which
are integral parts of higher dimensional Einstein--YM (EYM) systems, are
studied. These are the gravity decoupling limits of the fully gravitating EYM
solutions. In odd spacetime dimensions, depending on the choice of gauge group,
these are either topologically stable or unstable. Both cases are analysed, the
latter numerically only. In even spacetime dimensions they are always unstable,
describing saddle points of the energy, and can be described as {\it
sphalerons}. This instability is analysed by constructing the noncontractible
loops and calculating the Chern--Simons (CS) charges, and also perturbatively
by numerically constructing the negative modes. This study is restricted to the
simplest YM system in spacetime dimensions , which is amply
illustrative of the generic case.Comment: 16 pages, 3 figures ; comments added, to appear in J. Phys.
Particle-like solutions to higher order curvature Einstein--Yang-Mills systems in d dimensions
We consider the superposition of the first two members of the gravitational
hierarchy (Einstein plus first Gauss-Bonnet(GB)) interacting with the
superposition of the first two members of the Yang--Mills
hierarchy, in dimensions. Such systems can occur in the low energy
effective action of string theory. Particle-like solutions %for the systems
with only an Einstein term, and with only a GB term, in dimensions are
constructed respectively. Our results reveal qualitatively new properties
featuring double-valued solutions with critical behaviour. In this preliminary
study, we have restricted ourselves to one-node solutions.Comment: 10 pages, 11 figure
Interaction Energy of `t Hooft-Polyakov Monopoles
The dependence of the energies of axially symmetric monopoles of magnetic
charges 2 and 3, on the Higgs self-interaction coupling constant, is studied
numerically. Comparing the energy per unit topological charge of the charge-2
monopole with the energy of the spherically symmetric charge-1 monopole, we
confirm that there is only a repulsive phase in the interaction energy between
like monopolesComment: 6 pages, including 1 postscript figure, LaTex2e forma
A Frequency Analysis Approach for Categorizing Air Traffic Behavior
A method of analyzing National Air Space (NAS) air traffic that uses the Discrete Fourier Transform (DFT) is presented. The DFT is used to transform time domain traffic count data into the frequency domain where the sources of traffic in air spaces can be identified and characterized more easily. It is shown in simulation that individual traffic flows within Air Route Traffic Control Centers can be distinguished by their periodicity in the DFT plot. Next, three Traffic Management Initiatives (playbook rerouting, metered flows, and Ground Delay Programs) are implemented in simulations and their signature effects on the traffic are identified using the DFT. Finally, historical flight data is studied and the DFT is applied to sector traffic count data. It is found that in many cases, variations in traffic due to rerouting and convective weather disturbances are better highlighted in the frequency domain than in the original time domain data. Initial results of the DFT show it has potential as a tool for measuring and/or predicting NAS behavior for daily tactical planning and control purposes
Solitons in a Baby-Skyrme model with invariance under area preserving diffeomorphisms
We study the properties of soliton solutions in an analog of the Skyrme model
in 2+1 dimensions whose Lagrangian contains the Skyrme term and the mass term,
but no usual kinetic term. The model admits a symmetry under area preserving
diffeomorphisms. We solve the dynamical equations of motion analytically for
the case of spinning isolated baryon type solitons. We take fully into account
the induced deformation of the spinning Skyrmions and the consequent
modification of its moment of inertia to give an analytical example of related
numerical behaviour found by Piette et al.. We solve the equations of motion
also for the case of an infinite, open string, and a closed annular string. In
each case, the solitons are of finite extent, so called "compactons", being
exactly the vacuum outside a compact region. We end with indications on the
scattering of baby-Skyrmions, as well as some considerations as the properties
of solitons on a curved space.Comment: 30 pages, 5 figures, revtex, major modifications, conclusions
modifie
Dilute Instanton Gas of an O(3)Skyrme Model
The pure-Skyrme limit of a scale-breaking Skyrmed O(3) sigma model in 1+1 dimensions is employed to study the effect of the Skyrme term on the semiclassical analysis of a field theory with instantons. The instantons of this model are self-dual and can be evaluated explicitly. They are also localised to an absolute scale, and their fluctuation action can be reduced to a scalar subsystem. This permits the explicit calculation of the fluctuation determinant and the shift in vacuum energy due to instantons. The model also illustrates the semiclassical quantisation of a Skyrmed field theory
New axially symmetric Yang-Mills-Higgs solutions with negative cosmological constant
We construct numerically new axially symmetric solutions of SU(2)
Yang-Mills-Higgs theory in anti-de Sitter spacetime. Two types of
finite energy, regular configurations are considered: multimonopole solutions
with magnetic charge and monopole-antimonopole pairs with zero net
magnetic charge. A somewhat detailed analysis of the boundary conditions for
axially symmetric solutions is presented. The properties of these solutions are
investigated, with a view to compare with those on a flat spacetime background.
The basic properties of the gravitating generalizations of these configurations
are also discussed.Comment: 18 pages, 7 figures; v2: typos correcte