相关论文: Comments on "Solar System constraints to general f…
Recently, gravitational microlensing has been investigated in the framework of the weak field limit of fourth order gravity theory. However, solar system data (i.e. planetary periods and light bending) can be used to put strong constraints…
In this comment we point out some problems with the approach used in the paper "Newtonian limit of String-Dilaton Gravity" in the attempt to explain the properties of a weak field approximation for gravity theories.
In this communication we discuss the Weak Field Approach, and in particular the Newtonian limit, applied to f(R)-Gravity. Particular emphasis is placed on the spherically symmetric solutions and finally, it is clearly shown that General…
We investigate a simple generalization of the metric exponential $f(R)$ gravity theory that is cosmologically viable and compatible with solar system tests of gravity. We show that, as compared to other viable $f(R)$ theories, its steep…
We show that any analytic $f(R)$-gravity model, in the metric approach, presents a weak field limit where the standard Newtonian potential is corrected by a Yukawa-like term. This general result has never been pointed out but often derived…
We consider some models of f(R) gravity that can be used to describe, in a suitable weak-field limit, the gravitational field of the Sun. Using a perturbative approach, we focus on the impact that the modifications of the gravitational…
We use recent observations from solar system orbital motions in order to constrain f(T) gravity. In particular, imposing a quadratic f(T) correction to the linear-in-T form, which is a good approximation for every realistic case, we extract…
Using the elegant method employed recently by Erickcek, Smith and Kamionkowski, on the premise that the space-time of Solar System is described by a metric with constant-curvature background added by a static perturbation, we show that many…
We investigate the solar-system constraint on the f(R) theory of modified gravity with chameleon mechanism, where f(R) represents the deviation from general relativity in the gravity action. We obtain a stringent bound to a general,…
We motivate and analyze the weak-field limit of a non-analytical Lagrangian for the gravitational field. After investigating the parameter space of the model, we impose constraints on the parameters characterizing this class of theories…
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,…
A critical comment on [N. Lanahan--Tremblay and V. Faraoni, 2007, {\it Class. Quantum Grav.}, {\bf 24}, 5667, arXiv:0709.4414] is given discussing the well-formulation of the Chauchy problem for $f(R)$-gravity in metric-affine theories.
In the framework of $f(T)$ theories of gravity, we solve the field equations for $f(T)=T+\alpha T^{n}$, in the weak-field approximation and for spherical symmetry spacetime. Since $f(T)=T$ corresponds to Teleparallel Gravity, which is…
It is shown the antisymmetric part of the metric tensor is the potential for the spin field. Various metricity conditions are discussed and comparisons are made to other theories, including Einstein's. It is shown in the weak field limit…
We examine general physical parameterisations for viable gravitational models in the $f(R)$ framework. This is related to the mass of an additional scalar field, called the scalaron, that is introduced by the theories. Using a simple…
We review the Cauchy problem for f(R) theories of gravity, in metric and metric-affine for- mulations, pointing out analogies and differences with respect to General Relativity. The role of conformal transformations, effective scalar fields…
We introduce a new approach for investigating the weak field limit of vacuum field equations in $f(R)$ gravity and we find the weak field limit of $f(R)=R+\mu ^4/R$ gravity. Furthermore, we study the strong gravity regime in $R+\mu^{4}/R$…
Extended gravity is widely constrained in different astrophysical and astronomical systems. Since these different systems are based on different scales it is not trivial to get a combined constraint that is based on different phenomenology.…
We extend the analysis of Chiba, Smith and Erickcek \cite{CSE} of Solar System constraints on $f(R)$ gravity to a class of nonminimally coupled (NMC) theories of gravity. These generalize $f(R)$ theories by replacing the action functional…
A review of the new of the problem of dark energy using modified gravity approach is considered. An explanation of the difficulties facing modern cosmology is given and different approaches are presented. We show why some models of gravity…