scholarly journals Growth of resonances and chaos for a spinning test particle in the Schwarzschild background

2020 ◽  
Vol 101 (2) ◽  
Author(s):  
Ondřej Zelenka ◽  
Georgios Lukes-Gerakopoulos ◽  
Vojtěch Witzany ◽  
Ondřej Kopáček
2012 ◽  
Vol 21 (11) ◽  
pp. 1250056 ◽  
Author(s):  
ANINDITA BHATTACHARJEE ◽  
ASHOK DAS ◽  
LEVI GREENWOOD ◽  
SUDHAKAR PANDA

We investigate the motion of a test particle in higher dimensions due to the presence of extended sources like Dp-branes by studying the motion in the transverse space of the brane. This is contrasted with the motion of a point particle in the Schwarzschild background in higher dimensions. Since Dp-branes are specific to 10-dimensional spacetime and exact solutions of geodesic equations for this particular spacetime has not been possible so far for the Schwarzschild background, we focus here to find the leading order solution of the geodesic equation (for motion of light rays). This enables us to compute the bending of light in both the backgrounds. We show that contrary to the well known result of no noncircular bound orbits for a massive particle, in Schwarzschild background, for d ≥ 5, the Dp-brane background does allow bound elliptic motion only for p = 6 and the perihelion of the ellipse regresses instead of advancement. We also find that circular orbits for photon are allowed only for p ≤ 3.


Author(s):  
David M. Wittman

General relativity explains much more than the spacetime around static spherical masses.We briefly assess general relativity in the larger context of physical theories, then explore various general relativistic effects that have no Newtonian analog. First, source massmotion gives rise to gravitomagnetic effects on test particles.These effects also depend on the velocity of the test particle, which has substantial implications for orbits around black holes to be further explored in Chapter 20. Second, any changes in the sourcemass ripple outward as gravitational waves, and we tell the century‐long story from the prediction of gravitational waves to their first direct detection in 2015. Third, the deflection of light by galaxies and clusters of galaxies allows us to map the amount and distribution of mass in the universe in astonishing detail. Finally, general relativity enables modeling the universe as a whole, and we explore the resulting Big Bang cosmology.


2009 ◽  
Vol 24 (18) ◽  
pp. 1443-1451 ◽  
Author(s):  
CARLOS LEIVA ◽  
JOEL SAAVEDRA ◽  
JOSÉ VILLANUEVA

In this paper we study the geodesic structure of the Schwarzschild black hole in rainbow gravity analyzing the behavior of null and time-like geodesic. We find that the structure of the geodesics essentially does not change when the semiclassical effects are included. However, we can distinguish different scenarios if we take into account the effects of rainbow gravity. Depending on the type of rainbow functions under consideration, inertial and external observers see very different situations in radial and non-radial motion of a test particle.


1991 ◽  
Vol 44 (2) ◽  
pp. 551-554 ◽  
Author(s):  
Carlos Kozameh ◽  
E. T. Newman ◽  
Carlo Rovelli

1961 ◽  
Vol 16 (1) ◽  
pp. 118-150 ◽  
Author(s):  
G Kalman ◽  
Amiram Ron
Keyword(s):  

2021 ◽  
pp. 2150150
Author(s):  
Abdullah A. Ansari ◽  
Elbaz I. Abouelmagd

In this work, we analyze the motion properties of the test particle, that has a variable mass within the frame of Hénon–Heiles system. We derive the equations of motion of the test particle which varies its mass according to Jean’s law. We also determine the quasi-Jacobi integral which shows the effective variation due to variable mass parameters. Further, we studied the locations of stationary points and their stability, after using Meshcherskii spacetime inverse transformations.


2021 ◽  
Author(s):  
Xiaozhou Zhao ◽  
Rony Keppens ◽  
Fabio Bacchini

<div> <div> <div> <p>In an idealized system where four magnetic islands interact in a two-dimensional periodic setting, we follow the detailed evolution of current sheets forming in between the islands, as a result of an enforced large-scale merging by magnetohydrodynamic (MHD) simulation. The large-scale island merging is triggered by a perturbation to the velocity field, which drives one pair of islands move towards each other while the other pair of islands are pushed away from one another. The "X"-point located in the midst of the four islands is locally unstable to the perturbation and collapses, producing a current sheet in between with enhanced current and mass density. Using grid-adaptive resistive magnetohydrodynamic (MHD) simulations, we establish that slow near-steady Sweet-Parker reconnection transits to a chaotic, multi-plasmoid fragmented state, when the Lundquist number exceeds about 3×10<sup>4</sup>, well in the range of previous studies on plasmoid instability. The extreme resolution employed in the MHD study shows significant magnetic island substructures. Turbulent and chaotic flow patters are also observed inside the islands. We set forth to explore how charged particles can be accelerated in embedded mini-islands within larger (monster)-islands on the sheet. We study the motion of the particles in a MHD snapshot at a fixed instant of time by the Test-Particle Module incorporated in AMRVAC (). The planar MHD setting artificially causes the largest acceleration in the ignored third direction, but does allow for full analytic study of all aspects leading to the acceleration and the in-plane, projected trapping of particles within embedded mini-islands. The analytic result uses a decomposition of the test particle velocity in slow and fast changing components, akin to the Reynolds decomposition in turbulence studies. The analytic results allow a complete fit to representative proton test particle simulations, which after initial non-relativistic motion throughout the monster island, show the potential of acceleration within a mini-island beyond (√2/2)c≈0.7c, at which speed the acceleration is at its highest efficiency. Acceleration to several hundreds of GeVs can happen within several tens of seconds, for upward traveling protons in counterclockwise mini-islands of sizes smaller than the proton gyroradius.</p> </div> </div> </div><div></div><div></div>


Sign in / Sign up

Export Citation Format

Share Document