scholarly journals A NEW DESCRIPTION OF COSMIC STRINGS IN BRANE WORLD SCENARIO

2008 ◽  
Vol 23 (24) ◽  
pp. 2023-2030
Author(s):  
YI-SHI DUAN ◽  
LI-DA ZHANG ◽  
YU-XIAO LIU
Keyword(s):  
Magnetic Flux ◽  
Cosmic String ◽  
Cosmic Strings ◽  
Current Theory ◽  
Brane World ◽  
Higgs Model ◽  
Gauge Potential ◽  
Topological Description ◽  
Topological Current ◽  
Effective Description

In the light of ϕ-mapping topological current theory, the structure of cosmic strings are obtained from the Abelian Higgs model, which is an effective description to the brane world cosmic string system. In this topological description of the cosmic string, combining the result of decomposition of U(1) gauge potential, we analytically reach the familiar conclusions that in the brane world scenario the magnetic flux of the cosmic string is quantized and the RR charge of it is screened.

Skyrmion Excitations in Graphene

2014 ◽  
Vol 887-888 ◽  
pp. 960-965 ◽  
Author(s):  
Bu Da Zhao ◽  
Ming Xiang
Keyword(s):  
Potential Theory ◽  
Limit Point ◽  
Bifurcation Theory ◽  
Current Theory ◽  
Gauge Potential ◽  
Topological Current ◽  
Mapping Theory

By making use of theφ-mapping topological current theory and the decomposition of gauge potential theory, we investigate the skyrmion excitations of (2+1)-dimensional graphene. It is shown that the topological numbers are Hopf indices and Brower degrees. Based on the bifurcation theory of theφ-mapping theory, it is founded that the skyrmions can be generated or annihilated at the limit point (the generation and annihilation of skyrmion-antiskyrmion pairs).

scholarly journals VACUUM POLARIZATION NEAR BRANE WORLD COSMIC STRING

2002 ◽  
Vol 17 (18) ◽  
pp. 1207-1214 ◽  
Author(s):  
YU. V. GRATS ◽  
A. A. ROSSIKHIN
Keyword(s):  
Gravitational Field ◽  
Cosmic String ◽  
Vacuum Polarization ◽  
Cosmic Strings ◽  
Brane World ◽  
Spatial Dimensions

Gravitational field of cosmic strings in theories with extra spatial dimensions differs significantly from that in the 4D Einstein's theory. This means that all gravity induced properties of cosmic strings need to be revised. Here we consider the effect of vacuum polarization outside a straight infinitely thin cosmic string embedded in RS2 brane world.

SKYRMION EXCITATIONS OF SPIN HALL EFFECT IN ATOMS

2009 ◽  
Vol 23 (16) ◽  
pp. 1975-1982 ◽  
Author(s):  
JI-BIAO WANG ◽  
JI-RONG REN
Keyword(s):  
Hall Effect ◽  
Bifurcation Point ◽  
Bifurcation Theory ◽  
Atomic System ◽  
Current Theory ◽  
Spin Hall Effect ◽  
Gauge Potential ◽  
Optical Fields ◽  
Topological Current ◽  
Mapping Theory

By making use of ϕ-mapping topological current theory and the decomposition of gauge potential theory, we investigate the skyrmion excitations of spin Hall effect induced by optical fields in neutral atomic system. It is shown that the topological structures of these skyrmions are characterized by ϕ-mapping topological numbers: Hopf indices and Brouwer degrees. Based on the bifurcation theory of ϕ-mapping theory, it is found that the skyrmions can be generated or annihilated at the limit point and they encounter, split or merge at the bifurcation point.

TOPOLOGICAL OBJECTS IN THE O(3) NONLINEAR SIGMA MODEL

2007 ◽  
Vol 22 (31) ◽  
pp. 2379-2386
Author(s):  
PENG-MING ZHANG ◽  
XI-GUO LEE ◽  
SHAO-FENG WU ◽  
YI-SHI DUAN
Keyword(s):  
Sigma Model ◽  
Topological Defects ◽  
Current Theory ◽  
Gauge Potential ◽  
Nonlinear Sigma Model ◽  
Dimensional Model ◽  
Vortex Lines ◽  
Dimensional Spacetime ◽  
Topological Current ◽  
Topological Charges

We study the topological defects in the nonlinear O(3) sigma model in terms of the decomposition of U(1) gauge potential. Time-dependent baby skyrmions are discussed in the (2+1)-dimensional spacetime with the CP1 field. Furthermore, we show that there are three kinds of topological defects–vortex lines, point defects and knot exist in the (3+1)-dimensional model, and their topological charges, locations and motions are determined by the ϕ-mapping topological current theory.

scholarly journals NOVEL TOPOLOGICAL INVARIANT IN THE U(1) GAUGE FIELD THEORY

2007 ◽  
Vol 22 (29) ◽  
pp. 2201-2208 ◽  
Author(s):  
YISHI DUAN ◽  
XINHUI ZHANG ◽  
LI ZHAO
Keyword(s):  
Field Theory ◽  
Gauge Field ◽  
Potential Theory ◽  
Three Dimensional ◽  
Current Theory ◽  
Topological Invariant ◽  
Gauge Potential ◽  
Gauge Field Theory ◽  
Knot Invariant ◽  
Topological Current

Based on the decomposition of U(1) gauge potential theory and the ϕ-mapping topological current theory, the three-dimensional knot invariant and a four-dimensional new topological invariant are discussed in the U(1) gauge field.

DECOMPOSITION OF SU(2) CONNECTION AND KNOT STRUCTURE IN SKYRME–FADDEEV MODEL

2008 ◽  
Vol 23 (09) ◽  
pp. 1447-1456
Author(s):  
JI-RONG REN ◽  
RAN LI ◽  
YI-SHI DUAN
Keyword(s):  
Current Theory ◽  
Topological Invariant ◽  
Gauge Potential ◽  
Gauge Invariant ◽  
Hopf Invariant ◽  
Linking Numbers ◽  
Vector Decomposition ◽  
Topological Current ◽  
Faddeev Model ◽  
Invariant Principle

In this paper, spinor and vector decomposition of SU(2) gauge potential are presented and their equivalence is constructed using a simple proposal. We also obtain the action of Skyrme–Faddeev model from the SU(2) massive gauge field theory which is proposed according to the gauge invariant principle. Then, the knot structure in Skyrme–Faddeev model is discussed in terms of the so-called ϕ-mapping topological current theory. The topological charge of the knot is characterized by the Hopf indices and the Brouwer degrees of ϕ-mapping, naturally. At last, we briefly discussed the topological invariant–Hopf invariant which describes the topology of these knots. It is shown that Hopf invariant is the total number of all the linking numbers and self-linking numbers of these knots.

scholarly journals Searching for gravitational-wave bursts from cosmic string cusps with the Parkes Pulsar Timing Array

2020 ◽  
Vol 501 (1) ◽  
pp. 701-712
Author(s):  
N Yonemaru ◽  
S Kuroyanagi ◽  
G Hobbs ◽  
K Takahashi ◽  
X-J Zhu ◽  
...  
Keyword(s):  
False Alarm ◽  
Gravitational Wave ◽  
Cosmic String ◽  
Cosmic Strings ◽  
False Alarm Probability ◽  
String Tension ◽  
Detection Algorithm ◽  
Pulsar Timing ◽  
Upper Limits ◽  
Pulsar Timing Array

ABSTRACT Cosmic strings are potential gravitational-wave (GW) sources that can be probed by pulsar timing arrays (PTAs). In this work we develop a detection algorithm for a GW burst from a cusp on a cosmic string, and apply it to Parkes PTA data. We find four events with a false alarm probability less than 1 per cent. However further investigation shows that all of these are likely to be spurious. As there are no convincing detections we place upper limits on the GW amplitude for different event durations. From these bounds we place limits on the cosmic string tension of Gμ ∼ 10−5, and highlight that this bound is independent from those obtained using other techniques. We discuss the physical implications of our results and the prospect of probing cosmic strings in the era of Square Kilometre Array.

scholarly journals Angle deficit and nonlocal gravitoelectromagnetism around a slowly spinning cosmic string

2020 ◽  
Vol 29 (14) ◽  
pp. 2043027
Author(s):  
Jens Boos
Keyword(s):  
Gravitational Field ◽  
Symmetry Breaking ◽  
Early Universe ◽  
Physical Interpretation ◽  
Cosmic String ◽  
Cosmic Strings ◽  
Radial Distance ◽  
Gravitomagnetic Field ◽  
Simply Connected

Cosmic strings, as remnants of the symmetry breaking phase in the Early universe, may be susceptible to nonlocal physics. Here, we show that the presence of a Poincaré-invariant nonlocality—parametrized by a factor [Formula: see text]—regularizes the gravitational field and thereby changes the properties of spacetime: it is now simply connected and the angle deficit around the cosmic string becomes a function of the radial distance. Similar changes occur for the nonlocal gravitomagnetic field of a rotating cosmic string, and we translate these mathematical facts into the language of nonlocal gravitoelectromagnetism and thereby provide a physical interpretation. We hope that these insights might provide a helpful perspective in the search for traces of nonlocal physics in our universe.

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