Related papers: Dark matter influence on black hole objects thermo…
It is a well-known truism, inspired on the general theory of relativity, that gravity gravitates. Here we suggest the possibility that dark matter may be caused by the gravitation of the metric. At first sight this seems impossible since…
High energy collisions of particles may have created tiny black holes in the early Universe, which might leave stable remnants instead of fully evaporating as a result of Hawking radiation. If the reheating temperature was sufficiently…
In this article, we propose different background models of extended theories of gravity, which are minimally coupled to the SM fields, to explain the possibility of genesis of dark matter without affecting the SM particle sector. We modify…
Recent discoveries of primordial black hole (PBH) candidates by means of high cadence microlensing open the way to a physical understanding of the formation of dark matter as a chapter in the thermal history of the Universe. Two…
We discuss the production of primordial black holes in an early matter dominated era, which typically takes place in string inspired early universe cosmological models. In particular, we consider a pre-big bang scenario (extending previous…
We show that primordial (nearly) extremal black holes with a wide range of masses from the Planck scale to around $10^9$ g could be cosmologically stable and explain dark matter, given a dark electromagnetism and a heavy dark electron. For…
The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro world and mechanisms of its symmetry breaking. In the early Universe heavy metastable particles can…
With the recent progress in observations of astrophysical black holes, it has become more important to understand in detail the physics of strongly gravitating horizonless objects. If the objects identified in the observations are indeed…
We show by explicit computations that there is a superficial inconsistency between the conventional first law of black hole thermodynamics and Bekenstein-Hawking area law for three types of regular black holes. The corrected form of the…
We develop a theory of dark matter based on a previously proposed picture, in which a complex vacuum scalar field makes the universe a superfluid, with the energy density of the superfluid giving rise to dark energy, and variations from…
Since a black hole does not emit light from its interior, nor does it have a surface on which light from nearby sources can be reflected, observational study of black hole physics requires observing the gravitational impact of the black…
In this paper, we study massive gravity in the presence of Born-Infeld nonlinear electrodynamics. First, we obtain metric function related to this gravity and investigate the geometry of the solutions and find that there is an essential…
Einstein gravitation is known to give rise to the formation of singularities at high densities unless the dominant energy condition is made invalid by the occurrence of new physics: we show that such a new physics can be the already present…
The pervasive presence in space of a flux of high-speed, electrically uncharged dark matter particles is examined here for potential consequences. Dark matter interactions with ordinary matter are considered, and a model of the dark matter…
Models of Co-Decaying dark matter lead to an early matter dominated epoch -- prior to BBN -- which results in an enhancement of the growth of dark matter substructure. If these primordial structures collapse further they can form primordial…
Questions about black holes in quantum gravity generally presuppose the presence of a horizon. Recently Carlip has shown that enforcing an initial data surface to be a horizon leads to the correct form for the Bekenstein-Hawking entropy of…
We elucidate how black holes form in trans-Planckian collisions. In the rest frame of one of the incident particles, the gravitational field of the other, which is rapidly moving, looks like a gravitational shock wave. The shock wave…
Uniqueness problem of static axially symmetric black hole in magnetic Universe filled with {\it dark matter} component has been considered. The {\it dark matter} model comprises the additional $U(1)$-gauge field ({\it dark photon})…
In this work the phenomenology of models possessing a non-minimal coupling between matter and geometry is discussed, with a particular focus on the possibility of describing the flattening of the galactic rotation curves as a dynamically…
We incorporate the effect of non-local gravitational self-energy to obtain a neutral, non-singular spacetime geometry. This is achieved by using a non-local gravitational theory inspired by T-duality, where particle mass is not point-like…