Related papers: Black Holes and Gravitational Properties of Antima…
We argue that the hypothesis of the gravitational repulsion between matter and antimatter can be tested at the Ice Cube, a neutrino telescope, recently constructed at the South Pole. If there is such a gravitational repulsion, the…
The gravitational collapse of a non-rotating, black-hole-forming massive star is studied by neutrino-radiation-hydrodynamical simulations for two different sets of realistic equation of state of dense matter. We show that the event will…
We show that the gravitational collapse of a black-hole terminates in the birth of a white-hole, due to repulsive gravitation (antigravitation); in particular, the infinite energy density singularity does NOT occur.
Propagation of fermion in curved space-time generates gravitational interaction due to the coupling between spin of the fermion and space-time curvature. This gravitational interaction, which is an axial-vector appears as CPT violating term…
It is shown that space curvature can be disposed of by properly taking into account gravitational self energies. This leads to a parameter free modification of Newton's law, violating Gauss theorem, which accounts for the crucial tests of…
Recently, the static spherically symmetric solution of the gravitational field equations have been found in theories describing massive graviton with spontaneous breaking of the Lorentz invariance. These solutions, which show off two…
Propagation of a fermion in curved space-time generates a gravitational interaction due to coupling of its spin with the space-time curvature connection. This gravitational interaction, which is an axial-four-vector multiplied by a four…
Propagation of fermions in curved space-time generates gravitational interaction due to coupling of its spin with space-time curvature connection. This gravitational interaction, which is an axial-four-vector multiplied by a four…
The possibility of a nonzero graviton mass has been widely pursued in the literature. In this work we investigate a black hole solution in massive gravity with a degenerate fiducial metric often used in the literature. We find that the end…
We consider accretion of matter onto a low mass black hole surrounded by ionized medium. We show that, because of higher mobility of protons than electrons, the black hole would acquire positive electric charge. If the black hole's mass is…
The particles of a dark matter due to gravitational interaction deviate from straight trajectories in the vicinity of a massive body. This causes their density to become inhomogeneous. The developed density contrast causes a gravitation…
We study neutrinos gravitationally scattered off a rotating supermassive black hole which is surrounded by a thin accretion disk with a realistic magnetic field. Neutrinos are supposed to be Dirac particles having a nonzero magnetic moment.…
We consider the effects of gravitons in the collapse of baryonic matter that forms a black hole. We first note that the effective number of (soft off-shell) gravitons that account for the (negative) Newtonian potential energy generated by…
The synthesis of heavy elements in the Universe presents several challenges. From one side the astrophysical site is still undetermined and on other hand the input from nuclear physics requires the knowledge of properties of exotic nuclei,…
Black holes harbor a spacetime singularity of infinite curvature, where classical spacetime physics breaks down, and current theory cannot predict what will happen. However, the singularity is invisible from the outside because strong…
We suggest that the eventual gravitational repulsion between matter and antimatter may be a key for understanding of the nature of dark matter and dark energy. If there is gravitational repulsion, virtual particle-antiparticle pairs in the…
Black holes are one of the most fascinating predictions of general relativity. They are the natural product of the complete gravitational collapse of matter and today we have a body of observational evidence supporting the existence of…
The Hawking-Penrose singularity theorem states that a singularity forms inside a black hole in general relativity. To remove this singularity one must resort to a more fundamental theory. Using a corrected dynamical equation arising in loop…
The production of antihydrogen by several research groups provides the opportunity to measure the gravitational behaviour of antimatter in the gravitational field of the Earth. The predictions in the literature range from normal attraction…
There has been renewed interest in the idea of antigravity -- that matter and antimatter repel gravitationally - in lieu of the recent beautiful ALPHA-g result for the free-fall acceleration of antihydrogen of $a_{\bar{H}}=(0.75\pm…