相关论文: Scattering of cosmic strings by black holes: loop …
We study the dynamics of a cosmic string loop captured by a rotating black hole, ignoring string reconnections. A loop is numerically evolved in Kerr spacetime, with the result that it turns into one or more growing or contracting…
This paper discusses the gravitational scattering of a straight, infinitely long test cosmic string by a black hole. We present numerical results that probe the two-dimensional parameter space of impact parameter and initial velocity and…
We consider the evolution of a cosmic string loop that is captured by a much more massive and compact black hole. We show that after several reconnections that produce ejections of smaller loops, the loop that remains bound to the black…
The scattering of a straight, infinitely long string by a rotating black hole is considered. We assume that a string is moving with velocity v and that initially the string is parallel to the axis of rotation of the black hole. We…
In theories with cosmic strings, a small fraction of string loops may collapse to form black holes. In this Letter, various constraints on such models involving black holes are considered. Hawking radiation from black holes, gamma and…
Multiple gauge theories predict the presence of cosmic strings with different mass densities $G\mu/c^2$. We derive an equation governing the perturbations of a rotating black hole pierced by a straight, infinitely long cosmic string along…
A rotating black hole threaded by an infinitely long cosmic string is studied in the framework of the Abelian Higgs model. We show that contrary to a common belief, in the presence of rotation the backreaction of the string does not induce…
Rotating black holes when attached to a cosmic string have their rotational energy extracted leading to a change in its spin and mass. The spin of a black hole can be measured using various methods for an accreting black hole in an X-ray…
Cosmic strings that are attached to rapidly spinning black holes can extract significant amounts of rotational energy and angular momentum. Here we study the effect on primordial black holes, which are expected to form with one or more…
We study the evolution of cosmic strings taking into account the frictional force due to the surrounding radiation. We consider small perturbations on straight strings, oscillation of circular loops and small perturbations on circular…
In this work the equation of circular loops of cosmic string possessing time-dependent tension is studied in the de Sitter spacetime. We find that the cosmic string loops with initial radius $r(t_{0})>0.707L$, L de Sitter radius, should not…
We develop the general formalism for joining, splitting and interconnection of closed and open strings. As an application, we study examples of fundamental cosmic string collisions leading to gravitational collapse. We find that the…
In this paper, we study the equation of circular loops with time-dependant tension in the BTZ black hole background. We obtain various cases where cosmic string loops finally collapse to form black holes. Also, we study effect of the BTZ…
The capture of a straight, infinitely long cosmic string by a rotating black hole with rotation parameter $a$ is considered. We assume that a string is moving with velocity $v$ and that initially the string is parallel to the axis of…
We examine the shadow cast by a Kerr black hole pierced by a cosmic string. The observable images depend not only on the black hole spin parameter and the angle of inclination, but also on the deficit angle yielded by the cosmic string. The…
In this paper the equation of circular loops of cosmic string with periodic tension is investigated in the Minkowski spacetime and Robertson-Walker universe respectively. We find that the cosmic string loops possessing this kind of…
Primordial black hole formation by cosmic string collapse is reconsidered when the winding number of the string is larger than the unity. The line energy density of the multiple winding string becomes greater than that of the single winding…
The fraction of cosmic string loops which collapse to form black holes is estimated using a set of realistic loops generated by loop fragmentation. The smallest radius sphere into which each cosmic string loop may fit is obtained by…
Cosmic strings and primordial black holes (PBHs) commonly and naturally form in many scenarios describing the early universe. Here we show that if both cosmic strings and PBHs are present, their interaction leads to a range of interesting…
Relativistic current carrying strings moving axisymmetrically on the background of a Kerr black hole are studied. The boundaries and possible types of motion of a string with a given energy and current are found. Regions of parameters for…