Further consideration is given to the efficiency of a class of black hole heat engines that perform mechanical work via the pdV terms present in the First Law of extended gravitational thermodynamics. It is noted that, when the engine cycle is a rectangle with sides parallel to the (p, V) axes, the efficiency can be written simply in terms of the mass of the black hole evaluated at the corners....

We present a characteristic algorithm for computing the perturbation of a Schwarzschild spacetime by means of solving the Teukolsky equation. We implement the algorithm as a characteristic evolution code and apply it to compute the advanced solution to a black hole collision in the close approximation. The code successfully tracks the initial burst and quasinormal decay of a black hole perturba...

We investigate the scalar field perturbations of the 4+1-dimensional Schwarzschild black hole immersed in a Gödel Universe, described by the Gimon-Hashimoto solution. This may model the influence of the possible rotation of the Universe upon the radiative processes near a black hole. In the regime when the scale parameter j of the Gödel background is small, the oscillation frequency is linearly...

We investigate the scalar field perturbations of the 4+1-dimensional Schwarzschild black hole immersed in a Gödel Universe, described by the Gimon-Hashimoto solution. This may model the influence of the possible rotation of the Universe upon the radiative processes near a black hole. In the regime when the scale parameter j of the Gödel background is small, the oscillation frequency is linearly...

The Mobile adhoc networks (MANETs) networks that are defined as the wireless self configuring networks that are capable of operating without the support of any fixed infrastructure and a central coordinator which makes the routing a complicated task. One of the main challenges in MANET is to design robust security solution that can protect MANET from various routing attacks. MANET is vulnerable...

An ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. In mobile ad hoc network, each mobile node acts as a host as well as a router. These nodes communicate to each other by hop-to-hop communication. A number of routing protocols like Ad Hoc On-Demand Distance Vecto...

Mobile ad hoc networks are networks composed of wireless devices to create a network with the ability for self-organization. These networks are designed as a new generation of computer networks to satisfy some specific requirements and with features different from wired networks. These networks have no fixed communication infrastructure and for communication with other nodes the intermediate no...

A black hole is a highly harmful stationary process residing in a node of a network and destroying all mobile agents visiting the node without leaving any trace. The Black Hole Search is the task of locating all black holes in a network by exploring it with mobile agents. We consider the problem of designing the fastest Black Hole Search, given the map of the network and the starting node. We s...

A black hole is a highly harmful stationary process residing in a node of a network and destroying all mobile agents visiting the node without leaving any trace. The Black Hole Search is the task of locating all black holes in a network, through the exploration of its nodes by a set of mobile agents. In this paper we consider the problem of designing the fastest Black Hole Search, given the map...

A black hole is a harmful host that destroys incoming agents without leaving any observable trace of such a destruction. The black hole search problem is to unambiguously determine the location of the black hole. A team of agents, provided with a network map and executing the same protocol, solves the problem if at least one agent survives and, within finite time, knows the location of the blac...