We show that puncture data for quasicircular binary black hole orbits allow a special gauge choice that realizes some of the necessary conditions for the existence of an approximate helical Killing vector field. Introducing free parameters for the lapse at the punctures we can satisfy the condition that the Komar and ADMmass agree at spatial infinity. Several other conditions for an approximate...

Consider a team of asynchronous agents that must explore an unknown graph G in presence of a black hole, a node which destroys all incoming agents without leaving any observable trace. Interagent communication and coordination is achieved using tokens that agents can pick up, carry, and drop on the nodes. It is known that, if the agents have a map of G, the problem can be solved with a constant...

We investigate herein the spin interaction during collisions between Kerr-(anti-)de Sitter black holes. The spin interaction potential depends on the relative rotation directions of the black holes, and this potential can be released as gravitational radiation upon collision. The energy of the radiation depends on the cosmological constant and corresponds to the spin interaction potential in th...

An essential task of UAV autonomy is automatic path planning. There are many evolutionary planners for Unmanned Aerial Vehicles (UAVs) that have been developed UAV community. In this paper a comparative study about performance of effective trajectory planners is done. Also an efficient version of black hole methodology has been introduced for single UCAV trajectory planning, and an enhancement ...

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 ...

We investigate thermodynamic curvatures of the Kerr and Reissner-Nordström (RN) black holes in spacetime dimensions higher than four. These black holes possess thermodynamic geometries similar to those in four dimensional spacetime. The thermodynamic geometries are the Ruppeiner geometry and the conformally related Weinhold geometry. The Ruppeiner geometry for d = 5 Kerr black hole is curved an...

We consider a black hole in a heat bath, and the whole system which consists of the black hole and the heat bath is isolated from outside environments. When the black hole evaporates, the Hawking radiation causes an energy flow from the black hole to the heat bath. Therefore, since no energy flow arises in an equilibrium state, thermodynamic state of the whole system is not in an equilibrium. T...