It is shown that the event horizon for 4D black holes or ds2 = 0 surfaces for multidimensional wormhole-like solutions reduces the amount of information necessary for defining all spacetime and hence satisfies the Hologram principle. This leads to the result that by matching two metrics on the ds2 = 0 surfaces (event horizon for 4D black holes) we can match only the metric components but not it...

Accurate and powerful computational methods developped by the author, based on the analytic resolution of the wave equation in the black hole background, allow to obtain the highly non trivial total absorption spectrum of the Black Hole. As well as phase shifts and cross sections (elastic and inelastic) for a wide range of energy and angular momentum, the angular distribution of absorbed and sc...

The exact black hole solution of 2D closed string theory has, as any other maximally extended Schwarzschild-like geometry, two asymptotically flat spacetime domains. One can get rid of the second domain by gauging the discrete symmetry on the SL(2,R)/U(1) coset that interchanges the two asymptotic domains and preserves the Kruskal time orientation everywhere in the Kruskal plane. Here it is sho...

Unbound outflows in the form of highly collimated jets and broad winds appear to be a ubiquitous feature of accreting black hole systems. The most powerful jets are thought to derive a significant fraction, if not the majority, of their power from the rotational energy of the black hole. Whatever the precise mechanism that causes them, these jets must, therefore, exert a braking torque on the b...

In recent years the threshold of black hole formation in spherically symmetric gravitational collapse has been studied for a variety of matter models. In this paper the corresponding issue is investigated for a matter model significantly different from those considered so far in this context. We study the transition from dispersion to black hole formation in the collapse of collisionless matter...

In this paper we present results from a new two-dimensional numerical relativity code used to study the interaction of gravitational waves with a black hole. The initial data correspond to a single black hole superimposed with time-symmetric gravita-tional waves (Brill waves). A gauge invariant method is presented for extracting the gravitational waves from the numerically generated spacetime. ...

The discovery of frame-dragging effects in binary pulsar timing experiments requires a compact companion with sufficiently large spin. A pulsar orbiting a fast rotating black hole could provide an appropriate test system. In this paper we address questions concerning the identification of a black hole companion in such a system, the measurability of the frame dragging caused by the rotation of ...

In Parikh and Wilczek’s original works, the laws of black hole thermodynamics are not referred and it seems that there is no relation between Hawking radiation via tunnelling and the laws of black hole thermodynamics in their works. However, taking examples for the R-N black hole and the Kerr black hole, we find that they are correlated and even consistent if the tunnelling process is a reversi...

Kerner and Mann’s recent work shows that, for an uncharged and non-rotating black hole, its Hawking temperature can be correctly derived by fermions tunnelling from its horizons. In this paper, our main work is to improve the analysis to deal with charged fermion tunnelling from the general dilatonic black holes, specifically including the charged, spherically symmetric dilatonic black hole, th...

Black hole attack is a very common type of security attack found in Mobile Adhoc Network (MANET). In Black hole attack, the malicious node attracts all the data packets towards it using some false means and affects the data transmission in many ways, such as dropping of the packets. Black hole attack is vulnerable to security in MANET routing protocol. The paper focuses to provide a snapshot on...