Related papers: Cosmic Gravitational Wave Background in String Cos…
The existence of scalar fields can be probed by observations of stochastic gravitational waves. Scalar fields mediate attractive forces, usually stronger than gravity, on the length scales shorter than their Compton wavelengths, which can…
For suitable cosmological backgrounds, thermal fluctuations of a gas of strings can generate a scale-invariant spectrum of cosmological fluctuations without requiring a phase of inflationary expansion. We highlight the key points of this…
The cosmic string contributes to our understanding and revelation of the fundamental structure and evolutionary patterns of the universe, unifying our knowledge of the cosmos and unveiling new physical laws and phenomena. Therefore, we…
Cosmic strings are a common prediction in many grand unified theories and a promising source of stochastic gravitational waves (GWs) from the early Universe. In this paper, we point out that the GW signal from cosmic strings produced at a…
For most of cosmic history, the evolution of our Universe has been governed by the physics of a 'dark sector', consisting of dark matter and dark energy, whose properties are only understood in a schematic way. The influence of these…
We discuss the detectability of gravitational waves with a time dependent mass contribution, by means of the stochastic gravitational wave observations. Such a mass term typically arises in the cosmological solutions of massive gravity…
Appearance of cosmic strings in the early Universe is a common manifestation of new physics typically linked to some high energy scale. In this paper, we discuss a different situation, where a model underlying cosmic string formation is…
I discuss the generation of a stochastic background of gravitational waves during a first order phase transition. I present simple general arguments which explain the main features of the gravitational wave spectrum like the $k^3$ power law…
The collection of individually resolvable gravitational wave (GW) events makes up a tiny fraction of all GW signals which reach our detectors, while most lie below the confusion limit and go undetected. Like voices in a crowded room, the…
This paper calculates the expected gravitational wave background (GWB) in the quasi-steady state cosmology (QSSC). The principal sources of gravitational waves in the QSSC are the minicreation events (MCE). With suitable assumptions the GWB…
Magnetars have already been a potential candidate as gravitational wave sources that could be detected by current and future terrestrial as well as ground based gravitational wave detectors. In this article, we focus on the gravitational…
The coupling of a stringlike fluid with ordinary matter and gravity may lead to a closed Universe with the dynamic of an open one. This can provide an alternative solution for the age and horizon problems. A study of density perturbations…
The wave effect in the gravitational lensing phenomenon by a straight cosmic string is investigated. The interference pattern is expressed in terms of a simple formula. We demonstrate that modulations of the interfered wave amplitude can be…
It is well known that energy fluxes will produce gravitational wave memory. The gravitational wave memory produced by background including cosmic microwave background (CMB), cosmic neutrino background (C$\nu$B), and gravitational wave…
With a reinterpretation of recent results, the GRACE Follow-On mission can be applied to gravitational wave astronomy. Existing GRACE Follow-On data constrain the stochastic gravitational wave background to $\Omega_{GW}<3.3\times10^{7}$ at…
We present a simple sandwich gravitational wave of the Robinson-Trautman family. This is interpreted as representing a shock wave with a spherical wavefront which propagates into a Minkowski background minus a wedge. (i.e. the background…
The first generation of gravitational wave interferometric detectors has taken data at, or close to, their design sensitivity. This data has been searched for a broad range of gravitational wave signatures. An overview of gravitational wave…
In this paper we consider an inflating universe with long straight cosmic string along z-axis. We show that the effect of cosmic string can be taken as a perturbation on the background of FRW metric. Then by doing cosmological perturbations…
We review the current observational status of string cosmology when confronted with experimental datasets. We begin by defining common observational parameters and discuss how they are determined for a given model. Then we review the…
Recently, multiple pulsar timing array collaborations have presented compelling evidence for a stochastic signal at nanohertz frequencies, potentially originating from cosmic strings. Cosmic strings are linear topological defects that can…