93 research outputs found
Zero Modes of Rotationally Symmetric Generalized Vortices and Vortex Scattering
Zero modes of rotationally symmetric vortices in a hierarchy of generalized
Abelian Higgs models are studied. Under the finite-energy and the smoothness
condition, it is shown, that in all models, self-dual vortices superimposed
at the origin have modes. The relevance of these modes for vortex
scattering is discussed, first in the context of the slow-motion approximation.
Then a corresponding Cauchy problem for an all head-on collision of
vortices is formulated. It is shown that the solution of this Cauchy problem
has a symmetry.Comment: 12 pages. late
Finite-Action Solutions of Higher-Order Yang-Mills-Higgs Theory in Four Dimensions
We study (generalized) Yang-Mills-Higgs theories with higher-order terms. We present topologically nontrivial finte-action solutions in a mini-model and discuss a more relevant model later. Although the ansatz we choose is not S0(4) symmetric it leads to SO(4) invariant action densities and is compatible with the equations of motion for a wide class of models
Instanton Induced Tunneling Amplitude at Excited States with the LSZ Method
Quantum tunneling between degenerate ground states through the central
barrier of a potential is extended to excited states with the instanton method.
This extension is achieved with the help of an LSZ reduction technique as in
field theory and may be of importance in the study of macroscopic quantum
phenomena in magnetic systems.Comment: 8 pages, LaTex, no figure
Expansion in the distance parameter for two vortices close together
Static vortices close together are studied for two different models in
2-dimen- sional Euclidean space. In a simple model for one complex field an
expansion in the parameters describing the relative position of two vortices
can be given in terms of trigonometric and exponential functions. The results
are then compared to those of the Ginzburg-Landau theory of a superconductor in
a magnetic field at the point between type-I and type-II superconductivity. For
the angular dependence a similar pattern emerges in both models. The
differences for the radial functions are studied up to third order.Comment: 14 pages, Late
The 1-soliton in the SO(3) gauged Skyrme model with mass term
The solitons of the SO(3) gauged Skyrme model with no pion-mass potential
were studied in Refs. {nl,jmp}. Here, the effects of the inclusion of this
potential are studied. In contrast with the (ungauged) Skyrme model, where the
effect of this potential on the solitons is marginal, here it turns out to be
decisive, resulting in very different dependence of the energy as a function of
the Skyrme coupling constant.Comment: new title, typos corrected, LaTeX, 8 pages, 4 figure
Instantonic dyons of Yang-Mills--Chern-Simons models in d=2n+1 dimensions, n>2
We investigate finite energy solutions of Yang-Mills--Chern-Simons systems in
odd spacetime dimensions, d=2n+1, with n>2. This can be carried out
systematically for all n, but the cases n=3,4 corresponding to a 7,8
dimensional spacetime are treated concretely. These are static and spherically
symmetric configurations, defined in a flat Minkowski background. The value of
the electric charge is fixed by the Chern-Simons coupling constant.Comment: 15 pages, 4 figure
Regular solutions to higher order curvature Einstein--Yang-Mills systems in higher dimensions
We study regular, static, spherically symmetric solutions of Yang-Mills
theories employing higher order invariants of the field strength coupled to
gravity in dimensions. We consider models with only two such invariants
characterised by integers and . These models depend on one dimensionless
parameter leading to one-parameter families of regular solutions,
obtainable by numerical solution of the corresponding boundary value problem.
Much emphasis is put on an analytical understanding of the numerical results.Comment: 34 pages, 12 figure
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.
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