Corotating binary systems of identical Kerr-Newman black holes

Unequal binary configurations of interacting Kerr black holes

“…First of all, the conditions on the axis and the one eliminating both magnetic charges were established and solved analytically through an appropriate parametrization that eventually allowed us the derivation of non-trivial formulas for the half-length horizons σ i , as a function of seven arbitrary physical parameters of the system {M i , J i , Q i , R}, i = 1, 2. As a matter of fact, such formulas are generalizations of the vacuum problem [1] and the electrostatic one [25], where also other simpler rotating models endowed with electric charges can be trivially found [6,22]. Subsequently, the whole thermodynamical characteristics of the BS have been also depicted by very concise expressions.…”

“…This physical representation permits us to gain more novel information whether one attempts to study the dynamical aspects related to the spin-spin interaction (repulsion or attraction) within the binary system (BS), when the coalescence among two BHs is carrying out, or even before such a process could take place, and it can only be succeeded by getting concise expressions for the half-length BH horizons σ 1 and σ 2 in terms of Komar parameters. On the other hand, more general descriptions of stationary axisymmetric binary BHs can be analyzed once the electromagnetic field to the aforementioned rotating systems [1] is added, nonetheless, it increases considerably the laborious task to obtain exact results, and for such a reason, alluding to their symmetric nature, we have considered first a pair of identical corotating charged binary BH models [6] where magnetic charges are not taken into account in the solution.…”

“…As has been previously outlined in Ref. [6], the Ernst potentials (E, Φ) [13] on the upper part of the symmetry axis conveniently can be written in the form…”

Metric for two unequal extreme Kerr-Newman black holes

“…In order to verify the accuracy of our result, for Q 1 = Q 2 = 0, it is possible to attain directly from Eq. (37) the result [29],…”