Related papers: Modified Gravity (MOG) and its test on galaxy clus…
We study the effect of modifications to General Relativity on large scale weak lensing observables. In particular, we consider three modified gravity scenarios: f(R) gravity, the DGP model, and TeVeS theory. Weak lensing is sensitive to the…
We suggest the modified gravity where some arbitrary function of Gauss-Bonnet (GB) term is added to Einstein action as gravitational dark energy. It is shown that such theory may pass solar system tests. It is demonstrated that modified GB…
The review is devoted to consideration of possible observational consequences of modified gravity theories, suggested for explanation of the contemporary accelerated expansion of the universe. The major attention is paid to F(R)-models. It…
We study weak gravitational lensing of galaxy clusters in terms of the MOND (MOdified Newtonian Dynamics) theory. We calculate shears and convergences of background galaxies for three clusters (A1689, CL0024+1654, CL1358+6245) and the mean…
The shadows cast by non-rotating and rotating modified gravity (MOG) black holes are determined by the two parameters mass $M$ and angular momentum $J=Ma$. The sizes of the shadows cast by the spherically symmetric static Schwarzschild-MOG…
We compare six models (including the baryonic model, two dark matter models, two modified Newtonian dynamics models and one modified gravity model) in accounting for the galaxy rotation curves. For the dark matter models, we assume NFW…
We review galaxy formation and dynamics under the MOND hypothesis of modified gravity, and compare to similar galaxies in Newtonian dynamics with dark matter. The aim is to find peculiar predictions both to discriminate between various…
The nature of the fuel that drives today's cosmic acceleration is an open and tantalizing mystery. We entertain the suggestion that the acceleration is not the manifestation of yet another new ingredient in the cosmic gas tank, but rather a…
A theory is proposed which allows explaining the observed flat galaxy rotation curves, without needing to invoke dark matter. Whereas other theories have been proposed in the past which realize the same, the present theory rests on basic…
A new class of modified gravity theories, made possible by subtle features of the canonical formulation of general covariance, naturally allows MOND-like behavior (MOdified Newtonian Dynamics) in effective space-time solutions without…
Modified Newtonian Dynamics (MOND) is an alternative to the dark matter hypothesis that attempts to explain the "missing gravity" problem in astrophysics and cosmology through a modification to objects' dynamics. Since its conception in…
Dynamical mass discrepancies in galaxies have two possible explanations: the existence of large amounts of dark matter or the breakdown of Newtonian gravity. True dark matter halos of galaxies could differ in several respects from apparent…
The impressive success of the standard cosmological model has suggested to many that its ingredients are all one needs to explain galaxies and their systems. I summarize a number of known problems with this program. They might signal the…
The presence of dark matter, though well established by indirect evidence, is yet to be observed directly. Various dark matter detection experiments running for several years have yielded no positive results. In view of these negative…
We propose, in a heuristic way, a relativistic modified gravity model as an alternative to particle dark matter at galactic scales. The model is based on a postulated preferred time foliation described by a dynamical scalar field called the…
The Modified dynamics (MOND) has been propounded as an alternative to Dark matter. It imputes the mass discrepancy in galaxy systems to failure of standard dynamics in the limit of small accelerations. After a brief description of the MOND…
In modified gravity theories that seek to explain cosmic acceleration, dwarf galaxies in low density environments can be subject to enhanced forces. The class of scalar-tensor theories, which includes f(R) gravity, predict such a force…
Many body gravity (MBG) is an alternate theory of gravity, which has been able to explain the galaxy rotation curves, the radial acceleration relation (RAR) and the wide binary stars (WBS). The genesis of MBG is a novel theory, which models…
When it comes to searches for extensions to general relativity, large efforts are being dedicated to accurate predictions for the power spectrum of density perturbations. While this observable is known to be sensitive to the gravitational…
Models of modified gravity introduce extra degrees of freedom, which for consistency with the data, should be suppressed at observable scales. In the models that share properties of massive gravity such a suppression is due to nonlinear…