18,075 research outputs found

### Topological current of point defects and its bifurcation

From the topological properties of a three dimensional vector order
parameter, the topological current of point defects is obtained. One shows that
the charge of point defects is determined by Hopf indices and Brouwer degrees.
The evolution of point defects is also studied. One concludes that there exist
crucial cases of branch processes in the evolution of point defects when the
Jacobian $D(\frac \phi x)=0$.Comment: revtex,14 pages,no figur

### Evolution of the Chern-Simons Vortices

Based on the gauge potential decomposition theory and the $\phi$-mapping
theory, the topological inner structure of the Chern-Simons-Higgs vortex has
been showed in detail. The evolution of CSH vortices is studied from the
topological properties of the Higgs scalar field. The vortices are found
generating or annihilating at the limit points and encountering, splitting or
merging at the bifurcation points of the scalar field $\phi .$Comment: 10 pages, 10 figure

### Topology of Knotted Optical Vortices

Optical vortices as topological objects exist ubiquitously in nature. In this
paper, by making use of the $\phi$-mapping topological current theory, we
investigate the topology in the closed and knotted optical vortices. The
topological inner structure of the optical vortices are obtained, and the
linking of the knotted optical vortices is also given.Comment: 11 pages, no figures, accepted by Commun. Theor. Phys. (Beijing, P.
R. China

### Generally Covariant Conservative Energy-Momentum for Gravitational Anyons

We obtain a generally covariant conservation law of energy-momentum for
gravitational anyons by the general displacement transform. The energy-momentum
currents have also superpotentials and are therefore identically conserved. It
is shown that for Deser's solution and Clement's solution, the energy vanishes.
The reasonableness of the definition of energy-momentum may be confirmed by the
solution for pure Einstein gravity which is a limit of vanishing Chern-Simons
coulping of gravitational anyons.Comment: 12 pages, Latex, no figure

### Disclination in Lorentz Space-Time

The disclination in Lorentz space-time is studied in detail by means of
topological properties of $\phi$-mapping. It is found the space-time
disclination can be described in term of a Dirac spinor. The size of the
disclination, which is proved to be the difference of two sets of su(2)% -like
monopoles expressed by two mixed spinors, is quantized topologically in terms
of topological invariants$-$winding number. The projection of space-time
disclination density along an antisymmetric tensor field is characterized by
Brouwer degree and Hopf index.Comment: Revtex, 7 page

### Angular Momentum Conservation Law for Randall-Sundrum Models

In Randall-Sundrum models, by the use of general Noether theorem, the
covariant angular momentum conservation law is obtained with the respect to the
local Lorentz transformations. The angular momentum current has also
superpotential and is therefore identically conserved. The space-like
components $J_{ij}$ of the angular momentum for Randall-Sundrum models are
zero. But the component $J_{04}$ is infinite.Comment: 10 pages, no figures, accepted by Mod. Phys. Lett.

### Angular Momentum of a Brane-world Model

In this paper we discuss the properties of the general covariant angular
momentum of a five-dimensional brane-world model. Through calculating the total
angular momentum of this model, we are able to analyze the properties of the
total angular momentum in the inflationary RS model. We show that the
space-like components of the total angular momentum of are all zero while the
others are non-zero, which agrees with the results from ordinary RS model.Comment: 8 pages; accepted by Chinese Physics

### Energy-momentum for Randall-Sundrum models

We investigate the conservation law of energy-momentum for Randall-Sundrum
models by the general displacement transform. The energy-momentum current has a
superpotential and are therefore identically conserved. It is shown that for
Randall-Sundrum solution, the momentum vanishes and most of the bulk energy is
localized near the Planck brane. The energy density is $\epsilon = \epsilon_0
e^{-3k \mid y \mid}$.Comment: 13 pages, no figures, v4: introduction and new conclusion added, v5:
11 pages, title changed and references added, accepted by Mod. Phys. Lett.

### Self-Dual Vortices in the Fractional Quantum Hall System

Based on the $\phi$-mapping theory, we obtain an exact Bogomol'nyi self-dual
equation with a topological term, which is ignored in traditional self-dual
equation, in the fractional quantum Hall system. It is revealed that there
exist self-dual vortices in the system. We investigate the inner topological
structure of the self-dual vortices and show that the topological charges of
the vortices are quantized by Hopf indices and Brouwer degrees. Furthermore, we
study the branch processes in detail. The vortices are found generating or
annihilating at the limit points and encountering, splitting or merging at the
bifurcation points of the vector field $\vec\phi$.Comment: 13 pages 10 figures. accepted by IJMP

### A new topological aspect of the arbitrary dimensional topological defects

We present a new generalized topological current in terms of the order
parameter field $\vec \phi$ to describe the arbitrary dimensional topological
defects. By virtue of the $% \phi$-mapping method, we show that the topological
defects are generated from the zero points of the order parameter field $\vec
\phi$, and the topological charges of these topological defects are topological
quantized in terms of the Hopf indices and Brouwer degrees of $\phi$-mapping
under the condition that the Jacobian $% J(\frac \phi v)\neq 0$. When $J(\frac
\phi v)=0$, it is shown that there exist the crucial case of branch process.
Based on the implicit function theorem and the Taylor expansion, we detail the
bifurcation of generalized topological current and find different directions of
the bifurcation. The arbitrary dimensional topological defects are found
splitting or merging at the degenerate point of field function $\vec \phi$ but
the total charge of the topological defects is still unchanged.Comment: 24 pages, 10 figures, Revte

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