Kerr geodesics, the Penrose process and jet collimation by a black hole
Annotatsiya
<i>Aims. <i/>We re-examine the possibility that astrophysical jet collimation may arise from the geometry of rotating black holes and the presence of high-energy particles resulting from a Penrose process, without the help of magnetic fields.<i>Methods. <i/>Our analysis uses the Weyl coordinates, which are revealed better adapted to the desired shape of the jets. We numerically integrate the 2D-geodesics equations.<i>Results. <i/>We give a detailed study of these geodesics and give several numerical examples. Among them are a set of perfectly collimated geodesics with asymptotes <i>ρ<i/> = parallel to the <i>z<i/>-axis, with only depending on the ratios and , where <i>a<i/> and <i>M<i/> are the parameters of the Kerr black hole, <i>E<i/> the particle energy and the Carter's constant.