Related papers: Gravitational Tensor and Acoustic Waves in A Radia…
We set analytical constraints on the parameter space of models of gravity containing a term quadratic in Weyl curvature $-\alpha C^2$. In this class of models, there are four propagating tensorial degrees of freedom, two vector degrees of…
Gravitational waves travel through the distributions of matter and dark energy during propagation. For this reason, gravitational waves emitted from binary compact objects serve as a useful tool especially to probe the nature of dark…
We revisit the calculation of gravitational radiation through the use of Weyl scalars. We point out several possible problems arising from gauge and tetrad ambiguities and ways to address them. Our analysis indicates how, relatively simple…
We present a comprehensive theoretical framework for gravitational wave (GW) propagation and their \textbf{nonlinear backreaction} in $f(R, G)$ modified gravity. By developing a scalar-tensor formulation with two auxiliary fields, we…
In this paper we examine gravitational radiation in higher order non-local gravity described by the non-local gravitational Lagrangian density $\mathcal{L}_{g}=R+\sum_{h=1}^{n}a_{h}R\Box^{-h}R$. This non-local theory of gravitation always…
We derive a compact analytical expression for the growth factor $\Upsilon$, which characterizes how the gravitational wave spectrum sourced by sound waves evolves in a universe with a generic expansion history. Assuming the dominant energy…
We analyze the polarization structure of gravitational waves in the framework of Extended Relativity (ER), using the deviation tensor as the fundamental observable quantity. Starting from the point-source solution, we derive the radiation…
The cosmological stochastic gravitational-wave background produced by the mildly non-linear evolution of density fluctuations is analyzed, in the frame of an Einstein-de Sitter model, by means of a fully relativistic perturbation expansion…
We study the propagation of gravitational waves carrying arbitrary information through isotropic cosmologies. The waves are modelled as small perturbations of the background Robertson-Walker geometry. The perfect fluid matter distribution…
We consider a gravitational model in a Weyl-Cartan space-time, in which the Weitzenb\"{o}ck condition of the vanishing of the sum of the curvature and torsion scalar is also imposed. Moreover, a kinetic term for the torsion is also included…
At second-order, scalar perturbations can source traceless and transverse perturbations to the metric, called induced gravitational waves (IGW). The apparent gauge-dependence of the IGW obscures the interpretation of the stochastic…
A generalized version of the Einstein equations in the 4-index form, containing the Riemann tensor linearly, is derived. It is shown, that the gravitational energy-momentum density tensor outside a source is represented across the Weyl…
The Riemann tensor is the cornerstone of general relativity, but as everyone knows it does not appear explicitly in Einstein's equation of gravitation. This suggests that the latter may not be the most general equation. We propose here for…
In this paper, we study the polarization of a gravitational wave (GW) emitted by an astrophysical source at a cosmic distance propagating through the Friedmann-Lema\^itre-Robertson-Walk universe. By considering the null geodesic deviations,…
We investigate the evolution of cosmological perturbations during de Sitter inflation in the Einstein-Chern-Simons-Weyl gravity. Primordial massive gravitational waves are composed of one scalar, two vector and four tensor circularly…
Modeling of gravitational waves (GWs) from binary black hole inspiral brings together early post-Newtonian waveforms and late quasinormal ringing waveforms. Attempts to bridge the two limits without recourse to numerical relativity involve…
We derive consistent equations for gravitational wave oscillations in bigravity. In this framework a second dynamical tensor field is introduced in addition to General Relativity and coupled such that one massless and one massive linear…
We analyze the propagation and polarization properties of high-frequency gravitational waves in Einstein-\AE ther theory on vorticity-free and slowly-varying backgrounds at both leading and next-to-leading orders within the geometric optics…
We use the basic equations that predict the emission of gravitational waves according to the Einstein gravitation theory to calculate the luminosities and the amplitudes of the waves generated by binary stars, pulsations of neutron stars,…
The nonlinear turbulent interactions between acoustic gravity waves are investigated using two dimensional nonlinear fluid simulations. The acoustic gravity waves consist of velocity and density perturbations and propagate across the…