相关论文: Current-carrying string loops in black-hole spacet…

We investigate the vacuum fermionic currents in the geometry of a compactified cosmic string on background of de Sitter spacetime. The currents are induced by magnetic fluxes running along the cosmic string and enclosed by the compact…

The string shooter experiment uses counter-rotating pulleys to propel a closed string forward. Its steady state exhibits a transition from a gravity dominated regime at low velocity towards a high velocity regime where the string takes the…

We discuss the problem of the motion of classical strings in some black hole and cosmological spacetimes. In particular, the null string limit (zero tension) of tensile strings is considered. We present some new exact string solutions in…

In the context of a string-inspired running vacuum model (RVM) of cosmology with anomalies and torsion-induced axion-like fields, we discuss quantum corrections to the corresponding energy density, in approximately de Sitter eras, during…

We rederive the equations of motion for relativistic strings, that is, one-dimensional elastic bodies whose internal energy depends only on their stretching, and use them to study circular string loops rotating in the equatorial plane of…

We investigate the connection between curved spacetime and the emergence of string-instabilities, following the approach developed by Loust\'{o} and S\'{a}nchez for de Sitter and black hole spacetimes. We analyse the linearised equations…

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…

We study the deformation of a long cosmic string by a nearby rotating black hole. We examine whether the deformation of a cosmic string, induced by the gravitational field of a Kerr black hole, may lead to the formation of a loop of cosmic…

String theory has strong implications for cosmology: it tells us that we cannot have a cosmological constant, that single-field slow-roll inflation is ruled out, and that black holes decay. We elucidate the origin of these statements within…

We present and describe an exact solution of Einstein's equations which represents a snapping cosmic string in a vacuum background with a cosmological constant $\Lambda$. The snapping of the string generates an impulsive spherical…

We compute the self-force acting on an electric charge at rest in Schwarzschild-de Sitter spacetimes, allowing the cosmological constant to be either positive or negative. In the case of a positive cosmological constant, we show that the…

Equations of motion of null cosmic strings near black holes, or other massive sources, are solved exactly in the weak field approximation. The stress-energy tensor of a null string in a curved spacetime is introduced and used to show how…

We consider scattering and capture of circular cosmic strings by a Schwarzschild black hole. Although being a priori a very simple axially symmetric two-body problem, it shows all the features of chaotic scattering. In particular, it…

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…

The existence and stability under linear perturbation of closed timelike curves in the spacetime associated to Schwarzschild black hole pierced by a spinning string are studied. Due to the superposition of the black hole, we find that the…

We discuss cosmic Nielsen-Olesen strings in space-times endowed with a positive cosmological constant. For the cylindrically symmetric, static free cosmic string, we discuss the contribution of the cosmological constant to the angle…

Using recent simulation results, we provide the mass and speed spectrum of cosmic string loops. This is the quantity of primary interest for many phenomenological signatures of cosmic strings, and it can be accurately predicted using…

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…

Asymptotic symmetries are expected to leave subtle but physically meaningful imprints on quantum probes of gravity, yet their manifestation in near-horizon dynamics remains incompletely understood. We examine this question for a closed…

We consider the gravitational field of infinite straight and stationary twisted Baby Skyrmion cosmic string. Using the approximate solution of Einstein equations, it is shown that the internal phase rotation (twist) along the string axis is…