Angle deficit & non-local gravitoelectromagnetism around a slowly spinning cosmic string

Transverse momentum as a source of gravitoelectromagnetism

Momentum can be regarded as a mass current that can be used as the source of the gravitoelectromagnetic field, which is the weak-field gravitational analogue of the classical electromagnetic field. Typically, gravitoelectromagnetic research considers only mass currents of convective type, which are collinear with the velocity vector field, but when one looks at charged fluids that interact with a background electromagnetic field or charged, spinning point-like matter, such as the Frenkel electron, or extended spinning mass distributions, such as the Dirac electron and the Weyssenhoff fluid, on…

Spinning straight cosmic strings with flat exterior solutions generically violate the weak energy condition

Any interior solution for a cylindrically symmetric, stationary cosmic string with flat exterior, spinning around its longitudinal axis, and without internal longitudinal currents ($g_{zz}=1$, $g_{tz}=0$), must somewhere violate the weak energy condition of standard general relativity. Existing interior solutions may be readily fixed by adding mass to the string above that generating its angular deficit, but at the cost of introducing an exterior gravitational field.

On A 5-Dimensional Spinning Cosmic String

We present a numerical solution of a stationary 5-dimensional spinning cosmic string in the Einstein-Yang-Mills (EYM) model, where the extra bulk coordinate $ψ$ is periodic. It turns out that when $g_{ψψ}$ approaches zero, i.e., a closed time-like curve (CTC) would appear, the solution becomes singular. When a negative cosmological constant is incorporated in the model, the solution becomes regular everywhere with angle deficit$<2π$. However, the cosmic string-like object has not all the desired asymptotic properties of the counterpart Abelian Nielsen-Olesen string. When we use a two point bou…

Magnetic brane solutions of Lovelock gravity with nonlinear electrodynamics

In this paper, we consider logarithmic and exponential forms of nonlinear electrodynamics as a source and obtain magnetic brane solutions of the Lovelock gravity. Although these solutions have no curvature singularity and no horizon, they have a conic singularity with a deficit angle. We investigate the effects of nonlinear electrodynamics and the Lovelock gravity on the value of deficit angle and find that various terms of Lovelock gravity do not affect deficit angle. Next, we generalize our solutions to spinning cases with maximum rotating parameters in arbitrary dimensions and calculate the…

Asymptotic behaviour of cylindrical waves interacting with spinning strings

We consider a family of cylindrical spacetimes endowed with angular momentum that are solutions to the vacuum Einstein equations outside the symmetry axis. This family was recently obtained by performing a complete gauge fixing adapted to cylindrical symmetry. In the present work, we find boundary conditions that ensure that the metric arising from this gauge fixing is well defined and that the resulting reduced system has a consistent Hamiltonian dynamics. These boundary conditions must be imposed both on the symmetry axis and in the region far from the axis at spacelike infinity. Employing s…

自旋1/2粒子在具有类空位错和位错的旋转宇宙弦时空中的狄拉克振子

Dirac Oscillator for Spin-1/2 Particles in a Spinning Cosmic String Spacetime with Spacelike Disclination and Dislocation

本研究在具有曲率和挠率的旋转宇宙弦时空中精确求解了自旋1/2粒子的狄拉克振子，获得了依赖于振子频率、角缺陷和挠率参数的能谱，并表明曲率和挠率解除简并，推广了平直时空的Moshinsky振子谱。