Comparison of cosmic string and superstring models to NANOGrav 12.5-year results

Abstract We study the axion strings with the electroweak gauge flux in the DFSZ axion model and show that these strings, called the electroweak axion strings, can exhibit superconductivity without fermionic zeromodes. We construct three types of electroweak axion string solutions. Among them, the string with W-flux can be lightest in some parameter space, which leads to a stable superconducting cosmic string. We also show that a large electric current can flow along the string due to the Peccei-Quinn scale much higher than the electroweak scale. This large current induces a net attractive force between the axion strings with the same topological charge, which opens a novel possibility that the axion strings form Y-junctions in the early universe.

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ON A RESULT CONCERNING THE BEHAVIOR OF A RELATIVISTIC QUANTUM SYSTEM IN THE COSMIC STRING SPACETIME

International Journal of Modern Physics A ◽

10.1142/s0217751x0904498x ◽

2009 ◽

Vol 24 (08n09) ◽

pp. 1549-1556 ◽

Cited By ~ 7

Author(s):

V. B. BEZERRA ◽

GEUSA DE A. MARQUES

Keyword(s):

Magnetic Field ◽

Energy Spectrum ◽

Dirac Equation ◽

Quantum System ◽

Relativistic Electron ◽

Coulomb Potential ◽

Cosmic String ◽

Relativistic Quantum

We consider the problem of a relativistic electron in the presence of a Coulomb potential and a magnetic field in the background spacetime corresponding to a cosmic string. We find the solution of the corresponding Dirac equation and determine the energy spectrum of the particle.

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

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3721 ◽

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.

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The spin-zero Duffin-Kemmer-Petiau equation in a cosmic-string space-time with the Cornell interaction

International Journal of Modern Physics A ◽

10.1142/s0217751x16501918 ◽

2016 ◽

Vol 31 (36) ◽

pp. 1650191 ◽

Cited By ~ 24

Author(s):

M. de Montigny ◽

M. Hosseinpour ◽

H. Hassanabadi

Keyword(s):

Gravitational Field ◽

Coordinate System ◽

Cosmic String ◽

Topological Defects ◽

Space Time ◽

Dkp Equation

In this paper, we study the covariant Duffin-Kemmer-Petiau (DKP) equation in the cosmic-string space-time and consider the interaction of a DKP field with the gravitational field produced by topological defects in order to examine the influence of topology on this system. We solve the spin-zero DKP oscillator in the presence of the Cornell interaction with a rotating coordinate system in an exact analytical manner for nodeless and one-node states by proposing a proper ansatz solution.

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