Marco Astorino
Abstract:
The transformation which adds (or removes) NUT charge when it is applied to electrovacuum, axisymmetric and stationary space-times is studied. After analysing the Ehlers and the Reina-Treves transformations we propose a new one more precise in the presence of the Maxwell electromagnetic field.
As an example the Kerr-Newman-NUT black hole is obtained with the help of this enhanced transformation.
Moreover a new analytical exact solution is built adding the NUT charge to the Majumdar-Papapetrou metric. It describes a stationary generalisation of an extreme couple of charged black holes. From the near-horizon analysis, its microscopic entropy, according to the Kerr/CFT correspondence, is found and the second law of black hole thermodynamics is discussed.
A Mathematica notebook (needs RGTC extra package) with the Majumdar-Papapetrou-NUT spacetime is available for download