scholarly journals Implications of gravitational-wave production from dark photon resonance to pulsar-timing observations and effective number of relativistic species

2020 ◽  
Vol 102 (12) ◽  
Author(s):  
Ryo Namba ◽  
Motoo Suzuki
Keyword(s):  
Gravitational Wave ◽  
Effective Number ◽  
Dark Photon ◽  
Pulsar Timing ◽  
Photon Resonance

scholarly journals Gravitational waves and dark photon dark matter from axion rotations

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Raymond T. Co ◽  
Keisuke Harigaya ◽  
Aaron Pierce
Keyword(s):  
Dark Matter ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Early Universe ◽  
Radial Direction ◽  
Particle Production ◽  
Baryon Asymmetry ◽  
Complex Field ◽  
Dark Photon ◽  
Pulsar Timing

Abstract An axion rotating in field space can produce dark photons in the early universe via tachyonic instability. This explosive particle production creates a background of stochastic gravitational waves that may be visible at pulsar timing arrays or other gravitational wave detectors. This scenario provides a novel history for dark photon dark matter. The dark photons may be warm at a level detectable in future 21-cm line surveys. For a consistent cosmology, the radial direction of the complex field containing the axion must be thermalized. We explore a concrete thermalization mechanism in detail and also demonstrate how this setup can be responsible for the generation of the observed baryon asymmetry.

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 Erratum: Placing limits on the stochastic gravitational-wave background using European Pulsar Timing Array data

2012 ◽  
Vol 425 (2) ◽  
pp. 1597-1597 ◽  
Author(s):  
R. van Haasteren ◽  
Y. Levin ◽  
G. H. Janssen ◽  
K. Lazaridis ◽  
M. Kramer ◽  
...  
Keyword(s):  
Gravitational Wave ◽  
Array Data ◽  
Pulsar Timing ◽  
Gravitational Wave Background ◽  
Pulsar Timing Array
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