Quadrature solution for the general relativistic motion of a satellite or a planet

1973 ◽  
Vol 8 (2) ◽  
pp. 235-244 ◽  
Author(s):  
John P. Vinti
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.


1999 ◽  
Vol 521 (1) ◽  
pp. 376-381 ◽  
Author(s):  
Atsuyuki Hayashi ◽  
Yoshiharu Eriguchi ◽  
Masa‐aki Hashimoto

Synthese ◽  
2021 ◽  
Author(s):  
Antonio Vassallo

AbstractThe dynamics of general relativity is encoded in a set of ten differential equations, the so-called Einstein field equations. It is usually believed that Einstein’s equations represent a physical law describing the coupling of spacetime with material fields. However, just six of these equations actually describe the coupling mechanism: the remaining four represent a set of differential relations known as Bianchi identities. The paper discusses the physical role that the Bianchi identities play in general relativity, and investigates whether these identities—qua part of a physical law—highlight some kind of a posteriori necessity in a Kripkean sense. The inquiry shows that general relativistic physics has an interesting bearing on the debate about the metaphysics of the laws of nature.


2021 ◽  
Vol 502 (2) ◽  
pp. 1843-1855
Author(s):  
Antonios Nathanail ◽  
Ramandeep Gill ◽  
Oliver Porth ◽  
Christian M Fromm ◽  
Luciano Rezzolla

ABSTRACT We perform 3D general-relativistic magnetohydrodynamic simulations to model the jet break-out from the ejecta expected to be produced in a binary neutron-star merger. The structure of the relativistic outflow from the 3D simulation confirms our previous results from 2D simulations, namely, that a relativistic magnetized outflow breaking out from the merger ejecta exhibits a hollow core of θcore ≈ 4°, an opening angle of θjet ≳ 10°, and is accompanied by a wind of ejected matter that will contribute to the kilonova emission. We also compute the non-thermal afterglow emission of the relativistic outflow and fit it to the panchromatic afterglow from GRB170817A, together with the superluminal motion reported from VLBI observations. In this way, we deduce an observer angle of $\theta _{\rm obs}= 35.7^{\circ \, \, +1.8}_{\phantom{\circ \, \, }-2.2}$. We further compute the afterglow emission from the ejected matter and constrain the parameter space for a scenario in which the matter responsible for the thermal kilonova emission will also lead to a non-thermal emission yet to be observed.


2021 ◽  
Vol 9 ◽  
Author(s):  
Fabien Quéré ◽  
Henri Vincenti

Abstract The quantum vacuum plays a central role in physics. Quantum electrodynamics (QED) predicts that the properties of the fermionic quantum vacuum can be probed by extremely large electromagnetic fields. The typical field amplitudes required correspond to the onset of the ‘optical breakdown’ of this vacuum, expected at light intensities >4.7×1029 W/cm2. Approaching this ‘Schwinger limit’ would enable testing of major but still unverified predictions of QED. Yet, the Schwinger limit is seven orders of magnitude above the present record in light intensity achieved by high-power lasers. To close this considerable gap, a promising paradigm consists of reflecting these laser beams off a mirror in relativistic motion, to induce a Doppler effect that compresses the light pulse in time down to the attosecond range and converts it to shorter wavelengths, which can then be focused much more tightly than the initial laser light. However, this faces a major experimental hurdle: how to generate such relativistic mirrors? In this article, we explain how this challenge could nowadays be tackled by using so-called ‘relativistic plasma mirrors’. We argue that approaching the Schwinger limit in the coming years by applying this scheme to the latest generation of petawatt-class lasers is a challenging but realistic objective.


1987 ◽  
Vol 121 ◽  
pp. 287-293
Author(s):  
C.J. Schalinski ◽  
P. Biermann ◽  
A. Eckart ◽  
K.J. Johnston ◽  
T.Ph. Krichbaum ◽  
...  

A complete sample of 13 flat spectrum radio sources is investigated over a wide range of frequencies and spatial resolutions. SSC-calculations lead to the prediction of bulk relativistic motion in all sources. So far 6 out of 7 sources observed with sufficient dynamic range by means of VLBI show evidence for apparent superluminal motion.


2021 ◽  
Vol 103 (12) ◽  
Author(s):  
Xiaobao Liu ◽  
Jiliang Jing ◽  
Zehua Tian ◽  
Weiping Yao

2004 ◽  
Vol 69 (4) ◽  
Author(s):  
Guillermo A. González ◽  
Patricio S. Letelier

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