相关论文: Probing quantum gravity at low energies

A population of very light primordial black holes which evaporate before nucleosynthesis begins is unconstrained unless the decaying black holes leave stable relics. We show that gravitons Hawking radiated from these black holes would…

It was recently shown that black holes could be bouncing stars as a consequence of quantum gravity. We investigate the astrophysical signals implied by this hypothesis, focusing on primordial black holes. We consider different possible…

Black holes can be produced in collapse of small-scale dark matter structures, which can happen at any time from the early to present-day universe. Microstructure black holes (MSBHs) can have a wide range of masses. Small MSBHs evaporate…

In our recently proposed quantum theory of gravity, the universe is made of `atoms' of space-time-matter (STM). Planck scale foam is composed of STM atoms with Planck length as their associated Compton wave-length. The quantum dispersion…

Non-perturbative quantum gravity prevents the formation of curvature singularities and may allow black holes to decay with a lifetime shorter than evaporation time. This, in connection with the existence of primordial black holes, could…

The origin of observed extremely high energy cosmic rays remains an astrophysical enigma. We show that a single evaporating primordial black hole should produce 8.5*10^14 particles over a 10^20 eV threshold. This emission results from…

This is a review of some recent developments on quantum gravity aspects of black hole physics. In particular, we focus on a scenario leading to the prediction of the existence of a Planck-mass quasi-stable object, that could form a…

Scale dependence of fundamental physical parameters is a generic feature of ordinary quantum field theory. When applied to gravity, this idea produces effective actions generically containing a running Newtonian coupling constant, from…

Black holes are extreme manifestations of general relativity, so one might hope that exotic quantum effects would be amplified in their vicinities, perhaps providing clues to quantum gravity. The commonly accepted treatment of quantum…

Applying the first and generalised second laws of thermodynamics for a realistic process of near critical black hole formation, we derive an entropy bound, which is identical to Bekenstein's one for radiation. Relying upon this bound, we…

Eliptical and bulge galaxies share a tight correlation of velocity distribution to both luminosity and black hole mass. There are similar orbital speeds for all galaxies of a given luminosity including dark matter (DM) at large radii. The…

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 formation of primordial black holes in the early universe in the Brans-Dicke scalar-tensor theory of gravity is investigated. Corrections to the threshold value of density perturbations are found. Above the threshold, the gravitational…

We argue that primordial black holes in the early universe can provide an efficient resolution of the Brustein-Steinhardt moduli overshoot problem in string cosmology. When the universe is created near the Planck scale, all the available…

Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular…

The Hawking process results in a monotonic decrease of the black hole mass, but a biased random walk of the black hole angular momentum. We demonstrate that this stochastic process leads to a significant fraction of primordial black holes…

Primordial black holes may have formed in the radiative era of the early Universe from the collapse of large enough amplitude perturbations of the metric. These correspond to non linear energy density perturbations characterized by an…

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…

The idea that the vacuum polarization process occurring during gravitational collapse to a black hole endowed with electromagnetic structure (EMBH) could be the origin of gamma ray bursts (GRBs) is further developed. EMBHs in the range 3.2…

In Einstein gravity, matter with an arbitrarily small density can be a black hole. Pressure in the star diverges if size of the star is smaller than 9/8 of the Schwarzschild radius, implying the gravitational collapse into a black hole. By…