Related papers: Gravitational solution to the Pioneer 10/11 anomal…
Cosmic acceleration is explained quantitatively, as an apparent effect due to gravitational energy differences that arise in the decoupling of bound systems from the global expansion of the universe. "Dark energy" is a misidentification of…
This paper continues previous work on a novel alternative model of gravity, based on the theory of fractional-dimension spaces applied to Newton's law of gravitation. In particular, our Newtonian Fractional-Dimension Gravity is now applied…
The situation with respect to the experiments is presented of a recently proposed model that gives an explanation of the Pioneer anomalous acceleration $a_{\rm P}$. The model is based on an idea already discovered by Einstein in 1907: the…
We investigate spacetimes in which the speed of light along flat 4D sections varies over the extra dimensions due to different warp factors for the space and the time coordinates (``asymmetrically warped'' spacetimes). The main property of…
We explore cosmology in the decoupling limit of a non-linear covariant extension of Fierz-Pauli massive gravity obtained recently in arXiv:1007.0443. In this limit the theory is a scalar-tensor model of a unique form defined by symmetries.…
The recent observations on the far quasars absorption lines spectra and comparison of these lines with laboratory ones provide a framework for explantation of these observations by considering a varying fine structure constant, over the…
Recently, Jaekel and Reynaud put forth a metric linear extension of general relativity which, in the intentions of its proponents, would be able, among other things, to provide a gravitational mechanism for explaining the Pioneer anomaly…
From a purely none-general relativistic standpoint, we solve the empty space Poisson equation ($\nabla^{2}\Phi=0$) for an azimuthally symmetric setting, i.e., for a spinning gravitational system like the Sun. We seek the general solution of…
Interest has focussed recently on low energy implications of a nontrivial scale invariant sector of an effective field theory with an IR fixed point, manifest in terms of ``unparticles'' with peculiar properties. If unparticle stuff exists…
In the pursuit of a general formulation for a modified gravitational theory at the non-relativistic level and as an alternative to the dark matter hypothesis, we construct a model valid over a wide variety of astrophysical scales. Through…
In spite of two hundred years of considerable efforts directed towards improvement in the experimental techniques, gravitational measurements have provided unsettled results for Newton's gravitational constant G. Analysis of the published…
Galileon gravity is a robust theoretical alternative to general relativity with a cosmological constant for explaining cosmic acceleration, with interesting properties such as having second order field equations and a shift symmetry. While…
Newton's inverse-square law of universal gravitation assumes constant mass. But mass increases with speed and perhaps with gravity. By SR, mass is increased over the rest mass by gamma. Rest mass is here postulated to increase under…
Applying Newtonian dynamics in five dimensions rather than four, to a universe that is closed, isotropic and expanding,suggests that under certain circumstances an additional and previously unidentified acceleration, a_A, can arise…
The {\it concordance} cosmological model has been successfully tested throughout the last decades. Despite its successes, the fundamental nature of dark matter and dark energy is still unknown. Modifications of the gravitational action have…
In the standard Einstein's theory the exterior gravitational field of any static and axially symmetric stellar object can be described by means of a single function from which we obtain a metric into a four-dimensional space-time. In this…
In this paper we put on the test the new mechanism of gravitational origin recently put forth by Jaekel and Reynaud in order to explain the Pioneer anomaly in the framework of their post-Einsteinian metric extension of general relativity.…
Extensions of the standard models of particle physics and cosmology often lead to long-range fifth forces with properties dependent on gravitational environment. Fifth forces on astrophysical scales are best studied in the cosmic web where…
Despite its remarkable agreement with gravity tests in the solar system, general relativity is challenged at larger scales. Large scale tests performed in the solar system by the Pioneer 10/11 probes have failed to confirm the expected…
The Pioneer 10 and 11 spacecraft yielded very accurate navigation that was limited only by a small, anomalous frequency drift of their carrier signals received by the NASA Deep Space Network (DSN). This discrepancy, evident in the data for…