相关论文: Illusions of general relativity in Brans-Dicke gra…
The standard tenet that Brans-Dicke theory reduces to general relativity in the omega-tends-to-infinity limit has been shown to be false when the trace of the matter energy-momentum tensor vanishes. The issue is clarified in a new approach…
The $\omega\to\infty$ limit of Brans-Dicke theory is studied with the help of the conformal transformation approach without resorting, however, to the conformal invariance property of this formalism, that is shown to be spurious.
It has long been demonstrated that the vacuum scalar-tensor theory in the Jordan-frame Brans-Dicke parametrization is form-invariant under conformal transformations, provided that a suitable transformation of the coupling parameter $\omega$…
Brans-Dicke gravity does not always reduce to General Relativity in the limit $\omega\to\infty$ for the coupling constant. This anomalous behavior is examined within the formalism of the first-order thermodynamics of scalar-tensor gravity.…
Generally the Brans-Dicke theory reduces to General Relativity in the limit $\omega\rightarrow\infty$ if the scalar field goes as $\phi\propto1/\omega$. However, it is also known that there are examples with $\phi\propto1/\sqrt{\omega}$…
We formulate a theory combining the principles of a scalar-tensor gravity and Rastall's proposal of a violation of the usual conservation laws. We obtain a scalar-tensor theory with two parameters $\omega$ and $\lambda$, the latter…
The possibility that a charged particle propagating in a gravitational field described by Brans-Dicke theory of gravity could emit Cerenkov radiation is explored. This process is kinematically allowed depending on parameters occurring in…
We study the Brans-Dicke theory of gravity in Riemann-Cartan space-times, and obtain general torsion solutions, which are completely determined by Brans-Dicke scalar field $\Phi$, in the false vacuum energy dominated epoch. The substitution…
The pure Brans-Dicke (BD) gravity with or without the cosmological constant $\Lambda $ has been taken as a model theory for the dark matter. Indeed, there has been a consensus that unless one modifies either the standard theory of gravity,…
A classification of Brans-Dicke theories of gravitation, based on the behaviour of the dimensionless gravitational coupling constant, is given. It is noted that the discussion takes place in the current literature, about which of the two…
Contrary to common belief, (electro)vacuum Brans-Dicke gravity does not reduce to general relativity for large Brans-Dicke coupling $\omega$, a problem which has never been fully solved. Two new approaches, independent from each other, shed…
The Brans-Dicke Theory of Gravity is one of the most promising alternatives to the Einstein's Theory of General Relativity. We have examined an action term with wrong signs for both the kinetic and mass terms for the scalar field and have…
It is now established that, contrary to common belief, (electro-)vacuum Brans-Dicke gravity does not reduce to general relativity for large values of the Brans-Dicke coupling $\omega$. Since the essence of experimental tests of…
We consider the Brans-Dicke theory in non-metricity gravity, which belongs to the family of symmetric teleparallel scalar-tensor theories. Our focus lies in exploring the implications of the conformal transformation, as we derive the…
We study q-stars in Brans-Dicke gravitational theory. We find that when the Brans-Dicke constant, $\omega_{\textrm{BD}}$, tends to infinity, the results of General Relativity are reproduced. For other values of $\omega_{\textrm{BD}}$, the…
We investigate how the gravitational field generated by line sources can be characterized in Brans-Dicke theory of gravity. Adapting an approach previously developed by Israel who solved the same problem in general relativity we show that…
Brans-Dicke gravity admits spherical solutions describing naked singularities rather than black holes. Depending on some parameters entering such a solution, stable circular orbits exist for all radius. One argues that, despite the fact…
In this paper first we study Brans-Dicke equations with the cosmological constant to find an exact solution in the spatially flat Robertson-Walker metric. Then we use Observational Hubble data, the baryon acoustic oscillation distance ratio…
We consider first generation scalar-tensor theories of gravitation in a completely generic form, keeping the transformation functions of the local rescaling of the metric and the scalar field redefinition explicitly distinct from the…
It is demonstrated that, unless the meaning of conformal transformations for the underlying geometrical structure is discussed on a same footing as it is done for the equations of the given gravity theory, the notion of "conformal…