Related papers: Constraints on Scalar-Tensor Theory of Gravity by …
Future space-based tests of relativistic gravitation-laser ranging to Phobos, accelerometers in orbit, and optical networks surrounding Earth-will constrain the theory of gravity with unprecedented precision by testing the inverse-square…
We calculate the rate of energy loss from compact astrophysical objects due to a scalar field in screened modified gravity models of the chameleon, dilaton and symmetron types. The cosmological evolution of the field results in a…
A simple general relativity theory for objects moving in gravitational fields is developed based on studying the behavior of an atom in a gravitational field. The theory is applied to calculate the satellite time dilation, light deflection…
If the presence of a gravitational field breaks the Lorentz symmetry valid for special relativity, an "absolute motion" might be detectable. We summarize a scalar theory of gravity with a such "ether", which starts from a tentative…
A tensor description of perturbative Einsteinian gravity about an arbitrary background spacetime is developed. By analogy with the covariant laws of electromagnetism in spacetime, gravito-electromagnetic potentials and fields are defined to…
We show how observations of the perturbation spectra produced during inflation may be used to constrain the parameters of general scalar-tensor theories of gravity, which include both an inflaton and dilaton field. An interesting feature of…
Scalar-tensor theory of gravity with non-minimal coupling is a fairly good candidate for dark energy, required to explain late-time cosmic evolution. Here we study the very early stage of evolution of the universe with a modified version of…
A theory of gravity with torsion is examined in which the torsion tensor is constructed from the exterior derivative of an antisymmetric rank two potential plus the dual of the gradient of a scalar field. Field equations for the theory are…
Modified theories of gravity have received a renewed interest due to their ability to account for the cosmic acceleration. In order to satisfy the solar system tests of gravity, these theories need to include a screening mechanism that…
With the continuous upgrade of detectors, more and more gravitational wave (GW) events were captured by the LIGO Scientific Collaboration and Virgo Collaboration (LVC), which offers a new avenue to test General Relativity and explore the…
Recently, a covariant spherically symmetric model of a black hole within the framework of loop quantum gravity (LQG), characterized by a quantum parameter $r_0$ or $\lambda$, has been proposed. To derive constraints on the LQG-corrected…
We study gravitational lensing and the bending of light in low energy scale (M_S) gravity theories with extra space-time dimensions n. We find that due to the presence of spin-2 Kaluza-Klein states from compactification, a correction to the…
Testing gravity by binary pulsars nowadays becomes a key issue. Screened modified gravity is a kind of scalar-tensor theory with screening mechanism in order to satisfy the tight Solar System tests. In this paper, we investigate how the…
In this work, we derive novel constraints on scalar-tensor theories from neutrino physics. Spatial variations of the background scalar field effectively generate density and position-dependent Standard Model masses, including neutrinos.…
The motivations for investigating a theory of gravitation based on a concept of "ether" are discussed-- a crucial point is the existence of an alternative interpretation of special relativity, named the Lorentz-Poincar\'e ether theory. The…
We study the screening mechanism in the most general scalar-tensor theories that leave gravitational waves unaffected and are thus compatible with recent LIGO/Virgo observations. Using the effective field theory of dark energy approach, we…
A novel constraint on $f(R)$ theories of gravity is obtained from the gravitational wave signal emitted from the binary neutron star merger event GW170817. The $f(R)$ theories possess an additional massive scalar degree of freedom apart…
The dynamical consequences of a bimetric scalar-tensor theory of gravity with a dynamical light speed are investigated in a cosmological setting. The model consists of a minimally-coupled self-gravitating scalar field coupled to ordinary…
The present acceleration of the Universe strongly indicated by recent observational data can be modeled in the scope of a scalar-tensor theory of gravity. We show that it is possible to determine the structure of this theory (the scalar…
We consider a scalar-tensor theory of gravitation with the scalar source being the trace of the stress-energy tensor of the scalar field itself and matter. We obtain an example of a numerical solution of the cosmological equations which…