Talk detail

Participant	Spirin, Pavel
Institution	Institute of Theoretical and Computational Physics, University of Crete - Voutes - Heraklion - Crete - Greece

Session	ES2	Accepted		Order	Time
Talk	Oral abstract	Title	Gravitational Bremsstrahlung from Massless-particle Collisions
Coauthors
Abstract	The angular and frequency characteristics of the gravitational radiation emitted in collisions of massless particles is studied perturbatively in the context of classical General Relativity for small values of the ratio $\alpha\equiv 2 r_S/b$ of the Schwarzschild radius over the impact parameter. The particles are described with their trajectories, while the contribution of the leading nonlinear terms of the gravitational action is also taken into account. The old quantum results are reproduced in the zero frequency limit \mbox{$\omega\ll 1/b$}. The radiation efficiency $\epsilon \equiv E_{\rm rad}/2E$ {\it outside} a narrow cone of angle $\alpha$ in the forward and backward directions with respect to the initial particle trajectories is given by \mbox{$\epsilon \sim \alpha^2$} and is dominated by radiation with characteristic frequency \mbox{$\omega \sim {\mathcal O}\kn(1/r_S)$}. The comparison with previous works and the known literature is presented. The talk is based on arXiv:1503.02016 (JHEP\textbf{06} (2015) 153).
Pdf file

Session	ES2	Accepted		Order	Time
Talk	Oral abstract	Title	Smith-Will Force in Higher Dimensions
Coauthors
Abstract	We compute the self-energy of a static classical point-like charge (coupled with scalar or vector field), localized at the distance $r\gg r_g$ outside the horizon of higher-dimensional Schwarzschild-Tangherlini black hole. We use the perturbation theory and obtain first orders for the electrostatic energy and corresponding self-force. For the computation we apply the dimensional-regularization technique, well-known in the quantum theory, where the formal expression for self-energy diverges. In the lowest-dimensional cases the results are compared with known ones in the literature. The difference between the odd and even dimensionalities with respect to the charged particles is discussed as well.
Pdf file

Session	BH4	Accepted		Order	Time
Talk	Oral abstract	Title	Gravitational Bremsstrahlung from Massless-particle Collisions
Coauthors
Abstract	The angular and frequency characteristics of the gravitational radiation emitted in collisions of massless particles is studied perturbatively in the context of classical General Relativity for small values of the ratio $\alpha\equiv 2 r_S/b$ of the Schwarzschild radius over the impact parameter. The particles are described with their trajectories, while the contribution of the leading nonlinear terms of the gravitational action is also taken into account. The old quantum results are reproduced in the zero frequency limit $\omega\ll 1/b$. The radiation efficiency $\epsilon \equiv E_{\rm rad}/2E$ outside a narrow cone of angle $\alpha$ in the forward and backward directions with respect to the initial particle trajectories is given by $\epsilon \sim \alpha^2$ and is dominated by radiation with characteristic frequency $\omega \sim {\mathcal O}\kn(1/r_S)$. The comparison with previous works and the known literature is presented. The talk is based on arXiv:1503.02016 (JHEP06(2015)153).
Pdf file