相关论文: The Fourth Gravity Test and Quintessence Matter Fi…
Screening mechanisms are essential features of dark energy models mediating a fifth force on large scales. We study the regime of strong scalar field nonlinearities, known as Vainshtein screening, in the most general scalar-tensor theories…
The almost simultaneous detection of gravitational waves and a short gamma-ray burst from a neutron star merger has put a tight constraint on the difference between the speed of gravity and light. In the four-dimensional scalar-tensor…
The field equations following from a Lagrangian L(R) will be deduced and solved for special cases. If L is a non-linear function of the curvature scalar, then these equations are of fourth order in the metric. In the introduction we present…
The exact metric of a Schwarzschild black hole in the true radiation gauge was recently reported. In this work, we base on this gravity and calculate the gravitational deflection of relativistic massive particles up to the fourth…
We employ the metric of Schwarzschild space surrounded by quintessential matter to study the trajectories of test masses on the motion of a binary system. The results, which are obtained through the gradually approximate approach, can be…
Starting from the coordinate system used by Einstein to find the bending of light rays by gravitational fields we calculate the effect of the Earth gravitational energy along a hypothetical photon null path on the geoid non inertial system.…
The observed accelerated cosmic expansion can be a signature of fourth\,-\,order gravity theories, where the acceleration of the Universe is a consequence of departures from Einstein General Relativity, rather than the sign of the existence…
The framework for considering the astronomical and cosmological observations in the context of scalar-tensor quintessence in which the quintessence field also accounts for a time dependence of the gravitational constant is developed. The…
This study investigates quantum gravity effects within the framework of an effective loop quantum gravity (LQG) black hole model parameterized by $\zeta$, utilizing precision measurements from solar system experiments and astrophysical…
This paper is a sequel of the series of papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022], being an immediate continuation and development of the latter of them. In the Friedmann universe, the equation $\Omega_0=2q_0$ holds ($\Omega$ is…
We consider the consequences of describing the metric properties of space- time through a quartic line element $ds^4=G_{\mu\nu\lambda\rho}dx^\mu dx^\nu dx^\lambda dx^\rho$. The associated "metric" is a fourth-rank tensor…
The implications of seven popular models of quintessence based on supergravity or M/string theory for the transition from a decelerating to an accelerating universe are explored. All seven potentials can mimic the LambdaCDM model at low…
We propose a new quintessence scenario in the brane cosmology, assuming that a quintessence field $Q$ is confined in our 3-dimensional brane world. With a potential $V(Q)= \mu^{\alpha+4} Q^{-\alpha}~(\alpha\geq 2)$, we find that the density…
This paper is the fourth in a series dedicated to the mathematically rigorous asymptotic analysis of gravitational radiation under astrophysically realistic setups. It provides an overview of the physical ideas involved in setting up the…
We propose a method by which one could use modified antimatter gravity experiments in order to perform a high-precision test of antimatter charge neutrality. The proposal is based on the application of a strong, external, vertically…
We investigate the logarithmic form of $f(Q,T)$ gravity with two different choices of matter Lagrangian such as: $\mathcal{L}_m = p$ and $\mathcal{L}_m = -\rho$. The parameters of the model has been constrained using Cosmic Chronometers…
Some form of missing energy may account for the difference between the observed cosmic matter density and the critical density. Two leading candidates are a cosmological constant and quintessence (a time-varying, inhomogenous component with…
The gravitational field with spin-2 is introduced naturally by the requirement that the Lagrangian is locally translation invariant in Minkowski spacetime. The interactions between the gravitational field and spin-1/2, 0, 1 matter fields…
We investigate the four solar system tests of gravity - perihelion precession, light bending, Shapiro time delay, gravitational redshift - in $f(T)$ gravity. In particular, we investigate the solution derived by Ruggiero and Radicella,…
Recent astrophysical observations have provided strong evidence that the present expansion of the universe is accelerating, powered by the energy density associated with a cosmological term. Assuming the latter to be not simply a constant…