In the present paper we consider, using our earlier results, the process of quantum gravitational collapse and argue that there exists the final quantum state when the collapse stops. This state, which can be called the “no-memory state”, reminds the final “no-hair state” of the classical gravitational collapse. Translating the “no-memory state” into classical language we construct the classica...

wireless ad hoc networks are composed of independent nodes managing the network without any infrastructure. the connection between nodes is provided by sending packages and by trusting to each other. therefore, using efficient and certain protocols is the essential requirement of these networks. due to special characteristics of wireless ad hoc networks such as lack of a fixed infrastructure, t...

When a black hole evaporates, there arises a net energy flow from the black hole into its outside environment due to the Hawking radiation and the energy accretion onto black hole. Exactly speaking, any thermal equilibrium state has no energy flow, and therefore the black hole evaporation is a nonequilibrium process. To study details of evaporation process, nonequilibrium effects of the net ene...

in recent years mobile networks have expanded dramatically, compared with other wireless networks. routing protocols in these networks are designed with the assumption that there is no attacker node, so routing protocols are vulnerable to various attacks in these networks. in this paper, we review the network layer attacks and then we simulate the impact of black hole attack on ad hoc on demand...

We study the compact binary population in star clusters, focusing on binaries containing neutron stars and black holes, using a self-consistent Monte Carlo treatment of dynamics and full stellar evolution. We find that the black holes experience strong mass segregation and become centrally concentrated. In the core the black holes interact strongly with each other and black hole-black hole bina...

We derive a universal upper bound to the entropy of a charged system. The entropy bound follows from application of the generalized second law of thermodynamics to a gedanken experiment in which an entropy-bearing charged system falls into a charged black hole. This bound is stronger than the Bekenstein entropy bound for neutral systems. Black-hole physics mirrors thermodynamics in many respect...

We propose a method for measuring the black hole charge by imaging a black hole shadow in a galactic center by future interferometers. Even when the black hole is uncharged, it is possible to confirm the charge neutrality by this method. We first derive the analytic formulae of the black hole shadow in an optically thin medium around a charged spinning black hole, and then investigate how conto...

A toy model for the Blandford-Znajek mechanism is investigated: a Kerr black hole with a toroidal electric current residing in a thin disk around the black hole in the equatorial plane. The toroidal electric current generates a poloidal magnetic field threading the black hole and disk. The rotation of the black hole and disk relative to the magnetic field induces an electromotive force, which c...

The objectivity of black hole entropy is discussed in the particular case of a Schwarzchild black hole. Using Jaynes' maximum entropy formalism and Euclidean path integral evaluation of partition function , it is argued that in the semiclassical limit when the fluctutation of metric is neglected, the black hole entropy of a Schwarzchild black hole is equal to the maximal information entropy of ...