Self–gravitating cosmic rings
نویسنده
چکیده
The classical Einstein–Maxwell field equations admit static horizonless wormhole solutions with only a circular cosmic string singularity. We show how to extend these static solutions to exact rotating asymptotically flat solutions. For a suitable range of parameter values, these solutions describe charged or neutral rotating closed cosmic strings, with a perimeter of the order of their Schwarzschild radius, carrying a current intensity which can be arbitrarily small. PACS: 04.20 Jb 04.40 Nr 98.80 Cq ∗E-mail: [email protected].
منابع مشابه
Can a Self-gravitating Thin Cosmic String Obey the Nambu-goto Dynamics ?
We assume that a self-gravitating string is locally described by a thin tube of matter represented by a " smoothed conical metric ". If we impose a specific constraint on the model of string then its central line obeys the Nambu-Goto dynamics in the limit where the radius of the tube tends to zero. If no constraint is added then the world sheet of the central line is totally geodesic. It is adm...
متن کامل1 Fragmentation in Kinematically Cold Disks
Gravity is scale free. Thus gravity may form similar structures in self-gravitating systems on different scales. Indeed, observations of the interstellar medium, spiral disks and cosmic structures, reveal similar characteristics. The structures in these systems are very lumpy and inhomo-geneous. Moreover some of these structures do not seem to be of random nature, but obey certain power laws. M...
متن کاملar X iv : g r - qc / 9 90 30 21 v 2 2 9 M ar 1 99 9 Self – gravitating fluid shells and their non – spherical oscillations in Newtonian theory
We summarize the general formalism describing surface flows in three–dimensional space in a form which is suitable for various astrophysical applications. We then apply the formalism to the analysis of non–radial perturbations of self–gravitating spherical fluid shells. Spherically symmetric gravitating shells (or bubbles) have been used in numerous model problems especially in general relativi...
متن کاملLocal stability criterion for self-gravitating disks in modified gravity
We study local stability of self-gravitating fluid and stellar disk in the context of modified gravity theories which predict a Yukawa-like term in the gravitational potential of a point mass. We investigate the effect of such a Yukawa-like term on the dynamics of self-gravitating disks. More specifically, we investigate the consequences of the presence of this term for the local stability of t...
متن کاملWarps and Cosmic
N-body simulations show that when infall reorientates the outer parts of a galactic halo by several degrees per Gyr, a self-gravitating disk that is embedded in the halo develops an integral-sign warp that is comparable in amplitude to observed warps. Studies of angular-momentum acquisition suggest that the required rate of halo reorientation is realistic for galaxies like the Milky Way.
متن کامل