scholarly journals Computing general-relativistic effects from Newtonian N-body simulations: Frame dragging in the post-Friedmann approach

2014 ◽  
Vol 89 (4) ◽  
Author(s):  
Marco Bruni ◽  
Daniel B. Thomas ◽  
David Wands
Keyword(s):  
Relativistic Effects ◽  
Frame Dragging ◽  
General Relativistic

scholarly journals Towards communication in a curved spacetime geometry

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Qasem Exirifard ◽  
Eric Culf ◽  
Ebrahim Karimi
Keyword(s):  
Gravitational Lensing ◽  
Quantum Communication ◽  
Space Station ◽  
Relativistic Effects ◽  
Quantum Network ◽  
De Sitter ◽  
Spacetime Geometry ◽  
Frame Dragging ◽  
Spacetime Curvature ◽  
General Relativistic

AbstractThe current race in quantum communication – endeavouring to establish a global quantum network – must account for special and general relativistic effects. The well-studied general relativistic effects include Shapiro time-delay, gravitational lensing, and frame dragging which all are due to how a mass distribution alters geodesics. Here, we report how the curvature of spacetime geometry affects the propagation of information carriers along an arbitrary geodesic. An explicit expression for the distortion onto the carrier wavefunction in terms of the Riemann curvature is obtained. Furthermore, we investigate this distortion for anti de Sitter and Schwarzschild geometries. For instance, the spacetime curvature causes a 0.10 radian phase-shift for communication between Earth and the International Space Station on a monochromatic laser beam and quadrupole astigmatism; can cause a 12.2% cross-talk between structured modes traversing through the solar system. Our finding shows that this gravitational distortion is significant, and it needs to be either pre- or post-corrected at the sender or receiver to retrieve the information.

scholarly journals MEASURING GRAVITOMAGNETIC EFFECTS BY MEANS OF RING LASERS

2013 ◽  
Vol 23 ◽  
pp. 125-134
Author(s):  
ANGELO TARTAGLIA
Keyword(s):  
Reference Frames ◽  
Beat Frequency ◽  
Relativistic Effects ◽  
De Sitter ◽  
Frame Dragging ◽  
Ring Lasers ◽  
Experimental Apparatus ◽  
Order Of Magnitude ◽  
General Relativistic ◽  
Good Probe

Light is a good probe for general relativistic effects. Exploiting the asymmetry of the propagation in the vicinity of a central rotating mass it is possible to use a ring laser in order to measure the frame dragging of the reference frames by the gravitational field of the Earth (Lense-Thirring effect). I shall present the G-GranSasso experiment whose objective is precisely to measure the Lense-Thirring and the de Sitter effects in a terrestrial laboratory. The experimental apparatus will be made of a set of at least three, differently oriented, ring lasers rigidly attached to a central "monument". The signal will be in the form of the beat frequency produced in the annular cavity of each laser by the rotational anisotropy. The laboratory will be located underground in the Laboratori Nazionali del Gran Sasso facility, in Italy. The required sensitivity is just one order of magnitude below the performance of the best existing instruments and the new design will attain it.

Beyond the Schwarzschild Metric

2018 ◽  
Author(s):  
David M. Wittman
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Gravitational Waves ◽  
Test Particle ◽  
Direct Detection ◽  
Relativistic Effects ◽  
Big Bang ◽  
Clusters Of Galaxies ◽  
General Relativistic ◽  
The Universe

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.

scholarly journals Relative depolarization of the black hole photon ring in GRMHD models of Sgr A* and M87*

2021 ◽  
Vol 503 (3) ◽  
pp. 4563-4575
Author(s):  
A Jiménez-Rosales ◽  
J Dexter ◽  
S M Ressler ◽  
A Tchekhovskoy ◽  
M Bauböck ◽  
...  
Keyword(s):  
Black Hole ◽  
Relativistic Effects ◽  
Image Features ◽  
Black Hole Mass ◽  
Magnetic Turbulence ◽  
Intensity Images ◽  
General Relativistic ◽  
Sharp Image ◽  
Sgr A ◽  
Magnetohydrodynamic Simulations

ABSTRACT Using general relativistic magnetohydrodynamic simulations of accreting black holes, we show that a suitable subtraction of the linear polarization per pixel from total intensity images can enhance the photon ring feature. We find that the photon ring is typically a factor of ≃2 less polarized than the rest of the image. This is due to a combination of plasma and general relativistic effects, as well as magnetic turbulence. When there are no other persistently depolarized image features, adding the subtracted residuals over time results in a sharp image of the photon ring. We show that the method works well for sample, viable GRMHD models of Sgr A* and M87*, where measurements of the photon ring properties would provide new measurements of black hole mass and spin, and potentially allow for tests of the ‘no-hair’ theorem of general relativity.

scholarly journals Probing general relativistic effects during active galactic nuclei X-ray eclipses

2011 ◽  
Vol 417 (1) ◽  
pp. 178-183 ◽  
Author(s):  
G. Risaliti ◽  
E. Nardini ◽  
M. Elvis ◽  
L. Brenneman ◽  
M. Salvati
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Relativistic Effects ◽  
X Ray ◽  
General Relativistic

scholarly journals The general relativistic effects on the magnetic moment in Earth’s gravity

2018 ◽  
Vol 2018 (8) ◽  
Author(s):  
Takahiro Morishima ◽  
Toshifumi Futamase ◽  
Hirohiko M Shimizu
Keyword(s):  
Magnetic Moment ◽  
Relativistic Effects ◽  
General Relativistic
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