1998/07/01 by S. P. Drake, Samuel Picton Drake, S. P. Drake P. Szekeres +1 · 152 citations
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Astrophysical Phenomena and Observations #Classical mechanics #Einstein #General relativity #Gravitation #High-pressure geophysics and materials #Kerr metric #Mathematical analysis #Mathematical physics #Mathematics #Metric (unit) #Physics #Pulsars and Gravitational Waves Research #Rotating black hole #Schwarzschild metric #Schwarzschild radius #Theoretical physics #Uniqueness #gr-qc
paper · pdf · doi:10.1023/a:1001920232180
published in General Relativity and Gravitation 32(3), 445-457 (Springer Science+Business Media) · 14 pages, no figures, submitted to Class. Quantum Grav
arxiv created 1998/07/01 · openalex publication_date 2000/03/01 · arxiv updated 2010/12/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
After the original discovery of the Kerr metric, Newman and Janis showed that this solution could be ``derived'' by making an elementary complex transformation to the Schwarzschild solution. The same method was then used to obtain a new stationary axisymmetric solution to Einstein's field equations now known as the Kerr-newman metric, representing a rotating massive charged black hole. However no clear reason has ever been given as to why the Newman-Janis algorithm works, many physicist considering it to be an ad hoc procedure or ``fluke'' and not worthy of further investigation. Contrary to this belief this paper shows why the Newman-Janis algorithm is successful in obtaining the Kerr-Newman metric by removing some of the ambiguities present in the original derivation. Finally we show that the only perfect fluid generated by the Newman-Janis algorithm is the (vacuum) Kerr metric and that the only Petrov typed D solution to the Einstein-Maxwell equations is the Kerr-Newman metric.