An heuristic semiclassical procedure that incorporates quantum gravity induced corrections in the description of photons and spin 1/2 fermions is reviewed. Such modifications are calculated in the framework of loop quantum gravity and they arise from the granular structure of space at short distances. The resulting effective theories are described by power counting non-renormalizable actions wh...

Quantum gravity is the theory that is expected to successfully describe systems that are under strong gravitational effects while at the same time being of an extreme quantum nature. When this principle is applied to the universe as a whole, we use what is commonly named “quantum cosmology”. So far we do not have a definite quantum theory of gravity or cosmology, but we have several promising a...

Globular clusters in the Milky Way have characteristic velocity dispersions that are consistent with the predictions of Newtonian gravity, and may be at odds with Modified Newtonian Dynamics (MOND) and possibly the cold dark matter model. We discuss a modified gravity (MOG) theory that can successfully model the velocity dispersions of GCs in the Galactic neighborhood. MOG produces velocity dis...

The ability to test general relativity in extreme gravity regimes using gravitational wave observations from current ground-based or future space-based detectors motivates the mathematical study of symmetries black holes modified theories gravity. In this paper we focus on spinning hole solutions two quadratic theories: dynamical Chern-Simons and scalar Gauss-Bonnet We compute principal null di...

we study local stability of self-gravitating fluid and stellar disk in the context of modified gravity theories which predict a yukawa-like term in the gravitational potential of a point mass. we investigate the effect of such a yukawa-like term on the dynamics of self-gravitating disks. more specifically, we investigate the consequences of the presence of this term for the local stability of t...

The three-phase-lag model and Green–Naghdi theory without energy dissipation are employed to study the deformation of a two-temperature fiber-reinforced medium with an internal heat source that is moving with a constant speed under a hydrostatic initial stress and the gravity field.  The modulus of the elasticity is given as a linear function of the reference temperature. The exact expressions ...