相关论文: Gravitational radiation in higher order non-local …
We discuss some main aspects of theories of gravity containing non-local terms in view of cosmological applications. In particular, we consider various extensions of General Relativity based on geometrical invariants as $f(R, \Box^{-1} R)$,…
Using the Sparling form and a geometric construction adapted to spacetimes with a 2-dimensional isometry group, we analyse a quasi-local measure of gravitational energy. We then study the gravitational radiation through spacetime junctions…
It is shown that detecting or setting an upper limit on the scalar gravitational radiation is a good experimental test of relativistic gravity theories. The relativistic tensor-field theory of gravitation is revised and it is demonstrated…
Modified gravity theories predict in general a non standard equation for the propagation of gravitational waves. Here we discuss the impact of modified friction and speed of tensor modes on cosmic microwave polarization B modes. We show…
Alternative theories of gravity predict the presence of massive scalar, vector, and tensor gravitational wave modes in addition to the standard massless spin~2 graviton of general relativity. The deflection and frequency shift effects on…
We analyze the propagation of gravitational waves in a medium containing bounded subsystems ("molecules"), able to induce significant Macroscopic Gravity effects. We establish a precise constitutive relation between the average quadrupole…
An outstanding question in modern Physics is whether general relativity (GR) is a complete description of gravity among bodies at macroscopic scales. Currently, the best experiments supporting this hypothesis are based on high-precision…
In a modified gravity theory, the propagation equation of gravitational waves will be presented in a non-standard way. Therefore this tenor mode perturbation of time-space, as a complement to the scalar mode perturbation, provides a unique…
In this review we examine the amplitude intensity associated to tensorial and non-tensorial polarization modes generated by binary systems at their inspiral stage, within the alternative theories of gravity of Brans Dicke, Rosen, and…
In massive scalar-tensor gravity, core-collapse supernovae are strong sources of scalar-polarized gravitational waves. These can be detectable out to large distance. The dispersive nature of the propagation of waves in the massive scalar…
General Relativity predicts only two tensor polarization modes for gravitational waves while at most six possible polarization modes are allowed in general metric theory of gravity. The number of polarization modes is determined by the…
Gravitational waves provide a unique window into gravity, cosmology, and high-energy physics, enabling the exploration of fundamental phenomena across a wide range of scales. This review presents a coherent and pedagogical framework that…
We study a noncovariant theory of gravitation based on the Lagrangian density $\sqrt{-g})^\omega R$, where $\omega$ is a constant. In particular, we study solutions that for $\omega=1$ reduces to the de Sitter, Kasner and LFRW (with perfect…
In nonlocal general relativity, linearized gravitational waves are damped as they propagate from the source to the receiver in the Minkowski vacuum. Nonlocal gravity is a generalization of Einstein's theory of gravitation in which…
An effective energy tensor for gravitational radiation is identified for uniformly expanding flows of the Hawking mass-energy. It appears in an energy conservation law expressing the change in mass due to the energy densities of matter and…
We generalize the known equivalence between higher order gravity theories and scalar tensor theories to a new class of theories. Specifically, in the context of a first order or Palatini variational principle where the metric and connection…
We have done a series of two-dimensional hydrodynamic simulations of the rotational collapse of a supernova core in axisymmetry. We have employed a realistic equation of state (EOS) and taken into account electron captures and neutrino…
We derive the gravitational waveform and gravitational-wave energy flux generated by a binary star system of compact objects (neutron stars or black holes), accurate through second post-Newtonian order ($O[(v/c)^4] \sim O[(Gm/rc^2)^2]$)…
The article reviews the current status of a theoretical approach to the problem of the emission of gravitational waves by isolated systems in the context of general relativity. Part A of the article deals with general post-Newtonian…
This article aims to transform the infinite-order Lagrangian density for ghost-free infinite-derivative linearized gravity into non-local. To achieve it, we use the theory of generalized functions and the Fourier transform in the space of…