riassunto2

Speaker_	Aliev, Alikram Nuhbalaoglu
Talk_	Rotating Braneworld Black Holes
Abstract_	\documentclass[aps,report]{revtex4} \begin{document} \title{\Large \bf Rotating Braneworld Black Holes} \author{\large A. N. Aliev} \affiliation{ Feza G\"ursey Institute, P.K. 6 \c Cengelk\" oy, 81220 Istanbul, Turkey} \maketitle \noindent Several strategies have been discussed in the literature to describe the braneworld black holes. First of all, it has been argued that if the radius of the horizon of a black hole on the brane is much smaller than the size of the extra dimensions $(\,r_{+} \ll L \,)$, the black hole, to a good enough approximation, can be described by the usual classical solutions of higher dimensional vacuum Einstein equations. In the opposite limit when ($\,r_{+} \gg L \,)$, the black hole becomes effectively four-dimensional with a finite extension along the extra dimensions. The first simple solution pertinent to the latter case in the Randall-Sundrum braneworld is based on the idea of a usual Schwarzschild metric on the brane that would look like a {\it black string} solution from the point of view of an observer in the bulk \cite{chr}. However, the black string solution exhibits curvature singularities at infinite extension along the extra dimension. In this report I shall discuss another strategy of finding an exact solution that describes black holes localized on a 3-brane in the Randall-Sundrum scenario. I shall specify the metric form induced on the 3-brane assuming a Kerr-Schild ansatz for it. With this ansatz the system of the effective gravitational field equations on the brane \cite{sms,ae1} becomes closed and the solution to this system turns out to be a Kerr-Newman type stationary axisymmetric black hole which possesses a {\it tidal} charge instead of a usual {\it electric} charge. The tidal charge has a five-dimensional origin and can be thought of as an imprint of the non-local gravitational effects from the bulk space. I shall also present a new solution that describes a rotating black hole on the brane carrying both tidal and electric charges. Finally, I shall discuss the physical properties of these solutions and their possible astrophysical consequences. \noindent The report will be based on a recent joint work with A. E. Gumrukcuoglu \cite{ae2}. \begin{thebibliography}{99} \bibitem{chr} A. Chamblin, S. W. Hawking and H. S. Reall, Phys. Rev. D {\bf 61} 065007 (2000) \bibitem{sms} T. Shiromizu, K. Maeda, and M. Sasaki, Phys. Rev. D {\bf 62}, 024012 (2000) \bibitem{ae1} A. N. Aliev and A. E. Gumrukcuoglu, Class. Quant. Grav. {\bf 21}, 5081 (2004). \bibitem{ae2} A. N. Aliev and A. E. Gumrukcuoglu, Phys. Rev. D {\bf 71}, 104027 (2005) \end{thebibliography} \end{document}