Related papers: May Negative Mass Objects exist in the sky?
The presence of exotic states of matter in neutron stars (NSs) is currently an open issue in physics. The appearance of muons, kaons, hyperons, and other exotic particles in the inner regions of the NS, favored by energetic considerations,…
Negative masses have long been explored, but their observational viability remains unclear. In this work, we develop a unified, observationally testable framework to constrain negative masses using both coupling level and dynamical probes.…
An approach is developed to find approximate solutions to the classical Newtonian problem of N bodies. Sets of N gravitating bodies having spherically symmetric mass distributions, small angular velocities (< 1 rad/s) and bounded position…
Cosmology yields the most restrictive limits on neutrino masses and conversely, massive neutrinos would contribute to the cosmic dark-matter density and would play an important role for the formation of structure in the universe. Neutrino…
The widely accepted dark matter hypothesis offers a seductive solution to missing mass problems (galaxies, clusters of galaxies, gravitational collapse in structure formation,...). However the physical nature of the Dark Matter itself is…
We construct the gravitating mass of an isolated composite system on asymptotically-flat spacetimes within conventional general relativity and investigate when this quantity is well defined. For stationary spacetimes, this quantity is known…
Since the 1930s, astronomical observations have accumulated evidence that our understanding of the dynamics of galaxies and groups of galaxies is grossly incomplete: assuming the validity of Newton's law of gravity on astronomical scales,…
Black Holes are possibly the most enigmatic objects in our Universe. From their detection in gravitational waves upon their mergers, to their snapshot eating at the centres of galaxies, black hole astrophysics has undergone an observational…
The evidence for the existence of dark matter in the universe is reviewed. A general picture emerges, where both baryonic and non-baryonic dark matter is needed to explain current observations. In particular, a wealth of observational…
Dark matter particles can form halos gravitationally bound to massive astrophysical objects. The Earth could have such a halo where depending on the particle mass, the halo either extends beyond the surface or is confined to the Earth's…
The existence of cosmological compact objects with very strong gravity is a prediction of General Relativity and an exact solution of the Einstein equations. These objects are called black holes and recently we had the first observations of…
Under the assumption that General Relativity (GR) correctly describes the phenomenology of our Universe, astronomical observations provide compelling evidence that (1) the dynamics of cosmic structure is dominated by dark matter (DM), an…
Massive gravity is a theory which has a tremendous amount of freedom to describe different cosmologies; but at the same time the various solutions one encounters must fulfill some rather nontrivial constraints. Most of the freedom comes not…
Within the framework of Extended Space Model (ESM) the processes connected to birth of photons in a gravitational field are studied. These photons have a nonzero mass. It can be both positive, and negative, and photon's energy and strength…
The concept of exotic charged dust is introduced here to represent dark matter. The term "exotic" means that the dust is not composed of normal matter, and the charge--for lack of a better term--is not an electric charge. It is also shown…
Gravitational wave astronomy might allow us to detect the coalescence of low-brightness astrophysical compact objects which are extremely difficult to be observed with current electromagnetic telescopes. Besides classical sources like black…
In a previous paper we have proposed a non--Newtonian, phenomenological description of the effective gravitational force acting between exotic dark matter and baryons, which was shown to fit well the kinematics in the inner regions of low…
In this work we investigate the existence of relativistic models for dark matter in the context of bimetric gravity, used here to reproduce the modified Newtonian dynamics (MOND) at galactic scales. For this purpose we consider two…
MOG is a fully relativistic modified theory of gravity based on an action principle. The MOG field equations are exactly solvable numerically in two important cases. In the spherically symmetric, static case of a gravitating mass, the…
The idea of the quantum state of the Universe described by some density matrix, i.e mixture of at least two vacua, the trivial symmetric and the nontrivial one with spontaneously broken symmetry is discussed. Nonzero cosmological constant…