相关论文: Universal infrared scaling of gravitational wave b…
We consider the stochastic gravitational wave background induced by arbitrary source fields that are amplified during cosmological inflation. The associated tensor spectral index is shown to be given, under minimal assumptions, by a simple…
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…
We demonstrate that any scaling source in the radiation era produces a background of gravitational waves with an exact scale-invariant power spectrum. Cosmic defects, created after a phase transition in the early Universe, are such a…
Gravitational waves were copiously produced in the early Universe whenever the processes taking place were sufficiently violent. The spectra of several of these gravitational wave backgrounds on subhorizon scales have been extensively…
Induced gravitational waves provide a powerful probe of primordial perturbations in the early universe through their distinctive spectral properties. We analyze the spectral energy density $\Omega_{\text{GW}}$ of gravitational waves induced…
In light of the non-perturbative resonance effects that may occur during inflation, we introduce a parametrization for the power spectrum of the stochastic gravitational wave background (SGWB) characterized by narrow-band amplification. We…
We derive the complete spectrum of gravitational waves induced by primordial scalar perturbations ranging over all observable wavelengths. This scalar-induced contribution can be computed directly from the observed scalar perturbations and…
The energy spectrum of gravitational waves (GWs), which depicts the energy of GWs per unit volume of space per logarithmic frequency interval normalized to the critical density of the Universe, is a widely used way for quantifying the…
One of the predictions from simple inflation models is a stochastic background of gravitational waves (or literally what is called the Primordial Gravitational Waves (\textbf{PGW})) with a nearly scale--invariant spectrum. In this work, we…
We discuss long-lasting gravitational wave sources arising and operating during radiation-dominated stage. Under a set of assumptions, we establish the correspondence between cosmological evolution of a source and the resulting…
In this work, we revisit and evaluate new source terms which contribute to the induced gravitational wave background. We study their respective contributions to the stochastic gravitational wave background by computing their spectral…
We consider a generic dispersive massive gravity theory and numerically study its resulting modified energy and strain spectra of tensor gravitational waves (GWs) sourced by (i) fully developed turbulence during the electroweak phase…
Using a large N sigma model approximation we explicitly calculate the power spectrum of gravitational waves arising from a global phase transition in the early universe and we confirm that it is scale invariant, implying an observation of…
Physical scenarios, leading to highly energetic stochastic gravitational waves backgrounds (for frequencies ranging from the $\mu$Hz up to the GHz) are examined. In some cases the typical amplitude of the logarithmic energy spectrum can be…
The scalar perturbation induced gravitational waves are a probe of the primordial density perturbation spectrum on small scales. In this paper, we show that they can also probe the thermal history of the universe. We assume the universe…
We study the generation of gravitational radiation by sources moving in the de Sitter background. Exploiting the maximal symmetry and the conformal flatness of de Sitter space-time we prove that the derivation of this gravitational…
As a low energy effective field theory, classical General Relativity receives an infrared relevant modification from the conformal trace anomaly of the energy-momentum tensor of massless, or nearly massless, quantum fields. The local form…
Circumstances are described in which symmetry breaking during the formation of our three-dimensional brane within a higher-dimensional space in the early universe excites mesoscopic classical radion or brane-displacement degrees of freedom…
Usually, we assume that there is no inhomogeneity isotropic in terms of our location in the universe. This assumption has not been observationally confirmed yet in sufficient accuracy and we need to consider a method to restrict isotropic…
We put the upper bound on the gravitational waves (GWs) induced by the scalar-field fluctuations during the inflation. In particular, we focus on the case where the scalar fluctuations get amplified within some subhorizon scales by some…