相关论文: Life under a black sun

Black hole (BH) evaporation is caused by creation of entangled particle-antiparticle pairs near the event horizon, with one carrying positive energy to infinity and the other carrying negative energy into the BH. Since under the event…

Accreting black holes can release enormous amounts of energy to their surroundings, in various forms. Such feedback may profoundly influence a black hole's environment. After briefly reviewing the possible types of feedback, I focus on the…

The concept of black hole entropy is one of the most important enigmas of theoretical physics. It relates thermodynamics to gravity and allows substantial hints toward a quantum theory of gravitation. Although Bekenstein conjecture…

When a black hole is put in an "empty" space (zero temperature space) on which there is no matter except the matter of the Hawking radiation (Hawking field), then an outgoing energy flow from the black hole into the empty space exists. By…

Planck stars form when a collapsing shell of matter within a black hole reaches the Planck density, roughly equivalent to the mass being compressed into a volumetric size near that of the proton, and rebounds outwards. These planck stars…

Adopting the thin-layer improved brick-wall method, we investigate the thermodynamics of a black hole embedded in a spatially flat Friedmann-Robertson-Walker universe. We calculate the temperature and the entropy at every apparent horizon…

We obtain the dipolar anisotropies in the arrival directions of ultra-high energy cosmic rays diffusing from nearby extragalactic sources. We discuss both the energy regime of spatial diffusion and the quasi-rectilinear one leading to just…

We solve the Klein-Gordon equation for a scalar field, in the background geometry of a dust cloud collapsing to form a black hole, everywhere in the (1+1) spacetime: that is, both inside and outside the event horizon and arbitrarily close…

The gravitational waves and energy radiations from a spinning compact object with stellar mass in a circular orbit in the equatorial plane of a supermassive Kerr black hole are investigated in this paper. The effect how the spin acts on…

We investigate the meaning of the entropy carried away by Hawking radiations from a black hole. We propose that the entropy for a black hole measures the uncertainty of the information about the black hole forming matter's precollapsed…

A radiation-ball solution which is identified as a Reissner-Nordstrom black hole is found out. The radiation-ball, which is derived by analyzing the backreaction of the Hawking radiation into space-time, consists of radiation trapped in a…

Standard calculations suggest that the entropy of our universe is dominated by black holes, whose entropy is of order their area in Planck units, although they comprise only a tiny fraction of its total energy. Statistical entropy is the…

In the scalar theory of gravitation with a preferred reference frame, a consistent formulation of electrodynamics in the presence of gravitation needs to introduce an additional energy tensor: the interaction energy tensor. This energy is…

We consider the hypothesis that cosmic rays are emitted from the surfaces of neutron stars by a process of evaporation from an internal nuclear liquid to a dilute external gas which constitutes the "vacuum". On this basis, we find an…

Understanding the thermodynamic function of life may shed light on its origin. Life, as are all irreversible processes, is contingent on entropy production. Entropy production is a measure of the rate of the tendency of Nature to explore…

Scattering of particles in the gravitational field of rotating black holes is considered. It is shown that scattering energy of particles in the centre of mass system can obtain very large values not only for extremal black holes but also…

According to Blandford & Znajek (1977), energy can be extracted electromagnetically from a rotating black hole, should the latter be endowed with a magnetic field supported by electric currents in a surrounding disk. We show that exact…

Entropy plays a crucial role in characterization of information and entanglement, but it is not a scalar quantity and for many systems it is different for different relativistic observers. Loop quantum gravity predicts the…

The Universe owns the electronic radiation of blackbody at temperature 2.725 K, which we call the cosmic electron background. We calculate its radiation spectrum. The energy distribution of number density of electrons in the cosmic electron…

We stress the strongly observer-dependent nature of the fine-grained black hole entropy as computed by usual methods. From the point of view of a fiducial observer, the 1-loop renormalized energy-momentum tensor diverges at the horizon.…