Twisting of light around rotating black holes
2011 (English)In: Nature Physics, ISSN 1745-2473, E-ISSN 1745-2481, Vol. 7, no 3, 195-197 p.Article in journal (Refereed) Published
Kerr black holes are among the most intriguing predictions of Einstein's general relativity theory(1,2). These rotating massive astrophysical objects drag and intermix their surrounding space and time, deflecting and phase-modifying light emitted near them. We have found that this leads to a new relativistic effect that imprints orbital angular momentum on such light. Numerical experiments, based on the integration of the null geodesic equations of light from orbiting point-like sources in the Kerr black hole equatorial plane to an asymptotic observer(3), indeed identify the phase change and wavefront warping and predict the associated light-beam orbital angular momentum spectra(4). Setting up the best existing telescopes properly, it should be possible to detect and measure this twisted light, thus allowing a direct observational demonstration of the existence of rotating black holes. As non-rotating objects are more an exception than a rule in the Universe, our findings are of fundamental importance.
Place, publisher, year, edition, pages
2011. Vol. 7, no 3, 195-197 p.
IdentifiersURN: urn:nbn:se:uu:diva-149581DOI: 10.1038/NPHYS1907ISI: 000287844300014OAI: oai:DiVA.org:uu-149581DiVA: diva2:405148