Related papers: Gravitational wave spectrum from kinks on infinite…
Axions predicted in string theory may have a scalar potential which has a much shallower potential region than the conventional cosine potential. We first show that axions which were located at such shallow potential regions generically…
As one of the primary detection targets for contemporary gravitational wave (GW) observatories, the stochastic gravitational wave background (SGWB) holds significant potential for enhancing our understanding of the early universe's…
We study the stochastic gravitational wave (GW) background induced by the primordial scalar perturbation with the spectrum having a lognormal peak of width $\Delta$ at $k=k_*$. We derive an analytical formula for the GW spectrum…
Non-singular matter bouncing cosmological setups are of particular interest since apart from adressing the initial singularity problem they can give rise as well to a nearly scale-invariant curvature power spectrum on scales…
In a recent paper we have deduced the basic equations that predict the emission of gravitational waves (GW) according to the Einstein gravitation theory. In a subsequent paper these equations have been used to calculate the luminosities and…
The propagation of gravitational waves (GWs) at cosmological distances offers a new way to test the gravitational interaction at the largest scales. Many modified theories of gravity, usually introduced to explain the observed acceleration…
Recently the international pulsar timing array collaboration has announced the first strong evidence for an isotropic gravitational wave background (GWB). We propose that rapid small oscillations (wiggles) in the Hubble parameter would…
Stochastic gravitational-wave backgrounds (SGWBs) of primordial origin offer a powerful probe of early-Universe physics and possible dark-sector dynamics. While most searches focus on the GW power spectrum, additional information is encoded…
We investigate the new observational constraints on $f(T)$ gravity that arise from the effects of primordial gravitational waves (GWs) on the cosmic microwave background (CMB) anisotropies and the BB spectrum. We first show that on the GWs…
Compact Galactic binaries where at least one member is a white dwarf or neutron star constitute the majority of individually detectable sources for future low-frequency space-based gravitational-wave (GW) observatories; they also form an…
Cosmological domain walls appear in many well-motivated extensions to the standard model of particle physics. If produced, they quickly enter into a self-similar scaling regime, where they are capable of efficiently sourcing a stochastic…
Gravitational waves provide a unique and powerful opportunity to constrain the dynamics in the interior of proto-neutron stars during core collapse supernovae. Convective motions play an important role in generating neutron stars magnetic…
We discuss the gravitational wave background generated by primordial density perturbations evolving during the radiation era. At second-order in a perturbative expansion, density fluctuations produce gravitational waves. We calculate the…
According to the strange quark matter hypothesis, strange planets may exist, which are planetary mass objects composed of almost equal numbers of up, down and strange quarks. A strange planet can revolve around its host strange star in a…
We develop a semi-analytical model to describe the cosmological evolution of networks of cosmic strings with small-scale structure, by extending the velocity-dependent one-scale model to include an additional lengthscale describing the…
Recent exoplanet surveys have predicted a very large population of planetary systems in our galaxy, more than one planet per star on the average, perhaps totalling about two hundred billion. These surveys, based on electro-magnetic…
We compute the gravitational wave (GW) spectrum sourced by sound waves produced during a first-order phase transition in the radiation-dominated epoch. The correlator of the velocity field is evaluated in accordance with the sound shell…
We present a catalog of gravitational wave background (GWB) signal templates from cosmic-string networks, based on relevant models proposed in the literature. We classify templates as conventional, based on standard cosmology and Nambu-Goto…
Cosmic strings are predicted to form kinks and cusps that travel along the string at close to the speed of light. These disturbances are radiated away as highly beamed gravitational waves that produce a burst like pulse as the cone of…
The stochastic gravitational wave (GW) background provides a fascinating window to the physics of the very early universe. Beyond the nearly scale-invariant primordial GW spectrum produced during inflation, a spectrum with a much richer…