On the measurement of proper time in general relativity by means of atomic clocks

1981 ◽  
Vol 24 (1) ◽  
pp. 95-97
Author(s):  
B. V. Bondarev ◽  
Yu. R. Musin
Keyword(s):  
General Relativity ◽  
Proper Time ◽  
Atomic Clocks

scholarly journals Testing General Relativity with Atomic Clocks

2009 ◽  
Vol 148 (1-4) ◽  
pp. 233-247 ◽  
Author(s):  
S. Reynaud ◽  
C. Salomon ◽  
P. Wolf
Keyword(s):  
General Relativity ◽  
Atomic Clocks

scholarly journals Coordinate time in the vicinity of the Earth

1986 ◽  
Vol 114 ◽  
pp. 299-313 ◽  
Author(s):  
D. W. Allan ◽  
N. Ashby
Keyword(s):  
General Relativity ◽  
Atomic Clock ◽  
Space Vehicles ◽  
Atomic Clocks ◽  
Coordinate Time ◽  
The Earth ◽  
Frequency Comparison ◽  
New Applications ◽  
Frequency Metrology

Atomic clock accuracies continue to improve rapidly, requiring the inclusion of general relativity for unambiguous time and frequency clock comparisons. Atomic clocks are now placed on space vehicles and there are many new applications of time and frequency metrology. This paper addresses theoretical and practical limitations in the accuracy of atomic clock comparisons arising from relativity, and demonstrates that accuracies of time and frequency comparison can approach a few picoseconds and a few parts in 1016, respectively.

scholarly journals Strategies of motion under the black hole horizon

2020 ◽  
Vol 29 (03) ◽  
pp. 2030003
Author(s):  
A. V. Toporensky ◽  
O. B. Zaslavskii
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
First Principles ◽  
Proper Time ◽  
Black Hole Horizon ◽  
Schwarzschild Metric ◽  
Peculiar Velocity ◽  
Peculiar Velocities ◽  
Visible Part ◽  
Methodological Paper

In this methodological paper, we consider two problems an astronaut faces under the black hole horizon in the Schwarzschild metric. (1) How to maximize the survival proper time. (2) How to make a visible part of the outer universe as large as possible before hitting the singularity. Our consideration essentially uses the concept of peculiar velocities based on the “river model.” Let an astronaut cross the horizon from the outside. We reproduce from the first principles the known result that point (1) requires that an astronaut turn off the engine near the horizon and follow the path with the momentum equal to zero. We also show that point (2) requires maximizing the peculiar velocity of the observer. Both goals (1) and (2) require, in general, different strategies inconsistent with each other that coincide at the horizon only. The concept of peculiar velocities introduced in a direct analogy with cosmology and its application for the problems studied in this paper can be used in advanced general relativity courses.

Equations of state of continuous matter in general relativity

1970 ◽  
Vol 316 (1524) ◽  
pp. 1-28 ◽  
Keyword(s):  
General Relativity ◽  
Equations Of State ◽  
Proper Time ◽  
World Line ◽  
Time Lag ◽  
Strain Tensor ◽  
Rheological Behaviour ◽  
Physical Constant ◽  
Temperature History ◽  
Lie Derivative

The invariant forms that equations of state of continuous matter may take in general relativity, when the rheological behaviour of matter at any event may depend on previous rheological states through which that matter has passed, are discussed. A complete set of variables, needed in the general case to specify the relevant information about the matter at event x i , is first obtained as a set of space-tensors and then as a set of four-tensors orthogonal to the four-velocity at x i . These variables represent proper measures of deformation history, mechanical-stress history, temperature history, proper-time lag and physical constants of the material. An unambiguous definition is given of a physical constant (tensor) of the material (equation (122)). Elasticity, viscosity, and all possible combinations of these properties are within the scope of the theory. A detailed discussion is included of the processes of differentiation and integration of tensor quantities with respect to proper-time, following a particle along its world-line, such as will occur in equations of state in the general case. A convected integral with respect to proper-time is expressed (in equation (111)) in terms of displacement functions X 'm , which relate events x i and x 'm on the world-line of the same particle (such that x 'm is earlier than x i by an interval of proper-time t—t' ) through equations x 'm = X 'm (x i , t — t' ) . A convected derivative with respect to proper-time is expressed (in equation (82)) in terms of a Lie derivative defined with respect to the velocity vector field. Successive convected differentiation of a finite-strain tensor, defined in relation to an arbitrary reference configuration of a material element, gives rise to a sequence of rate-of-strain tensors.

Chronometric measurements in geodesy and geophysics

2020 ◽  
Author(s):  
Pacôme Delva ◽  
Guillaume Lion
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
High Spatial Resolution ◽  
Relativistic Effects ◽  
Atomic Clocks ◽  
Fundamental Physics ◽  
Geodynamic Processes ◽  
New Ideas ◽  
Mass Transfers

<p>At the beginning of the 20th century the theories of special and general relativity were developed by Einstein and his contemporaries. These physical theories revolutionize our conceptions of time and of the measurement of time. The atomic clocks, which appeared in the 1950s, are so accurate and stable that it is now essential to take into account many relativistic effects. The development and worldwide comparisons of such atomic clocks allowed for some of the most stringent of fundamental physics, as well as new ideas for the search of dark matter. On a more applied level, when taking general relativity for granted, distant comparisons of atomic clocks can be used for navigation and positioning, as well as the determination of the geopotential. I will show how the chronometric observables can fit and be used within the context of classical geodesy and geophysics, presenting various applications: determination of the geopotential with high spatial resolution, vertical reference system, and discussing the possible applications associated to the geodynamic processes related to mass transfers.</p>

scholarly journals Simultaneous determination of mass parameter and radial marker in Schwarzschild geometry

2021 ◽  
Author(s):  
Victor Varela ◽  
Lorenzo Leal
Keyword(s):  
General Relativity ◽  
Simultaneous Determination ◽  
Euclidean Geometry ◽  
Proper Time ◽  
Mass Parameter ◽  
Thought Experiments ◽  
Newtonian Gravity ◽  
Algebraic Equations ◽  
Schwarzschild Geometry

Abstract We show that mass parameter and radial marker values can be indirectly measured in thought experiments performed in Schwarzschild spacetime, without using the Newtonian limit of general relativity or approximations based on Euclidean geometry. Our approach involves different proper time quantifications as well as solutions to systems of algebraic equations, and aims to strengthen the conceptual independence of general relativity from Newtonian gravity.

scholarly journals Schwarzschild Field of a Proper Time Oscillator

Symmetry ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 312
Author(s):  
Hou Yau
Keyword(s):  
General Relativity ◽  
Proper Time ◽  
Point Mass ◽  
Schwarzschild Solution

In this paper, we show that an oscillator in proper time can mimic a point mass at rest in general relativity. The spacetime outside this proper time oscillator is static and satisfies the Schwarzschild solution.

scholarly journals Proper Time Dynamics in General Relativity and Conformal Unified Theory

1998 ◽  
Vol 30 (12) ◽  
pp. 1749-1773 ◽  
Author(s):  
L. N. Gyngazov ◽  
M. Pawlowski ◽  
V. N. Pervushin ◽  
V. I. Smirichinski
Keyword(s):  
General Relativity ◽  
Proper Time ◽  
Unified Theory ◽  
Time Dynamics

Space clocks to test relativiy: ACES and SAGAS

2009 ◽  
Vol 5 (S261) ◽  
pp. 377-389
Author(s):  
Peter Wolf ◽  
Christophe Salomon ◽  
Serge Reynaud
Keyword(s):  
General Relativity ◽  
Experimental Verification ◽  
Interplanetary Space ◽  
Space Missions ◽  
Atomic Clocks ◽  
Rapid Improvement ◽  
Pulsar Timing ◽  
Fundamental Astronomy

AbstractAtomic clocks are an outstanding tool for the experimental verification of general relativity and more generally for fundamental astronomy (VLBI, pulsar timing, navigation, etc). Recent years have seen a rapid improvement in the performance of such clocks, promising new improved tests of relativity, in particular onboard terrestrial and interplanetary space missions. We present the scientific motivations of such tests taking the ACES Salomon et al. and SAGAS Wolf et al. (2009) projects as particular examples.

scholarly journals Theory of quantum gravity beyond Einstein and space-time dynamics with quantum inflation

2015 ◽  
Vol 30 (28n29) ◽  
pp. 1545002 ◽  
Author(s):  
Yue-Liang Wu
Keyword(s):  
General Relativity ◽  
Quantum Gravity ◽  
Minkowski Space ◽  
Gauge Field ◽  
Gravitational Force ◽  
Proper Time ◽  
Space Time ◽  
Coordinate Space ◽  
Gauge Symmetries ◽  
Minkowski Space Time

In this talk, I present a theory of quantum gravity beyond Einstein. The theory is established based on spinnic and scaling gauge symmetries by treating the gravitational force on the same footing as the electroweak and strong forces. A bi-frame space-time is initiated to describe the laws of nature. One frame space-time is a globally flat coordinate Minkowski space-time that acts as an inertial reference frame for the motions of fields, the other is a locally flat non-coordinate Gravifield space-time that functions as an interaction representation frame for the degrees of freedom of fields. The Gravifield is sided on both the globally flat coordinate space-time and locally flat non-coordinate space-time and characterizes the gravitational force. Instead of the principle of general coordinate invariance in Einstein theory of general relativity, some underlying principles with the postulates of coordinate independence and gauge invariance are motivated to establish the theory of quantum gravity. When transmuting the Gravifield basis into the coordinate basis in Minkowski space-time, it enables us to obtain equations of motion for all quantum fields and derive basic conservation laws for all symmetries. The gravity equation is found to be governed by the total energy–momentum tensor defined in the flat Minkowski space-time. When the spinnic and scaling gauge symmetries are broken down to a background structure that possesses the global Lorentz and scaling symmetries, we arrive at a Lorentz invariant and conformally flat background Gravifield space-time that is characterized by a cosmic vector with a non-zero cosmological mass scale. We also obtain the massless graviton and massive spinnon. The resulting universe is in general not isotropic in terms of conformal proper time and turns out to be inflationary in light of cosmic proper time. The conformal size of the universe has a singular at the cosmological horizon to which the cosmic proper time must be infinitely large. We show a mechanism for quantum inflation caused by the quantum loop contributions. The Gravifield behaves as a Goldstone-like field that transmutes the local spinnic gauge symmetry into the global Lorentz symmetry, which makes the spinnic gauge field becomes a hidden gauge field. As a consequence, the bosonic gravitational interactions can be described by the Goldstone-like Gravimetric field and space-time gauge field. The Einstein theory of general relativity is expected to be an effective low energy theory. Two types of gravity equation are resulted, one is the extension to Einstein’s equation of general relativity, and the other is a new type of gravitational equation that characterizes the spinnon dynamics.

Sign in / Sign up

Export Citation Format

Share Document