The mass-energy of a finite body in general relativity

1977 ◽  
Vol 8 (12) ◽  
pp. 975-985 ◽  
Author(s):  
M. A. Oliver
Keyword(s):  
General Relativity ◽  
Mass Energy ◽  
Finite Body

scholarly journals CAN THE EXISTENCE OF DARK ENERGY BE DIRECTLY DETECTED?

2009 ◽  
Vol 24 (18n19) ◽  
pp. 3426-3436 ◽  
Author(s):  
MARTIN L. PERL
Keyword(s):  
General Relativity ◽  
Dark Energy ◽  
Energy Density ◽  
Total Mass ◽  
Mass Density ◽  
Mass Energy ◽  
Dark Energy Density ◽  
Astronomical Observations ◽  
Expansion Of The Universe ◽  
The Universe

Over the last decade, astronomical observations show that the acceleration of the expansion of the universe is greater than expected from our understanding of conventional general relativity, the mass density of the visible universe, the size of the visible universe and other astronomical measurements. The additional expansion has been attributed to a variety of phenomenon that have been given the general name of dark energy. Dark energy in the universe seems to comprise a majority of the energy in the visible universe amounting to about three times the total mass energy. But locally the dark energy density is very small. However it is not zero. In this paper I describe the work of others and myself on the question of whether dark energy density can be directly detected. This is a work-in-progress and I have no answer at present.

THE GRAVITY OF QUANTUM PRESSURE — A NEW TEST OF GENERAL RELATIVITY

2008 ◽  
Vol 17 (05) ◽  
pp. 747-753 ◽  
Author(s):  
C. S. UNNIKRISHNAN ◽  
G. T. GILLIES
Keyword(s):  
General Relativity ◽  
Small Volume ◽  
Empirical Investigation ◽  
Opposite Sign ◽  
Relativistic Quantum ◽  
Mass Energy ◽  
Quantum Matter ◽  
Energy Stress ◽  
Degeneracy Pressure ◽  
Precision Test

Matter confined to a small volume generates quantum pressure and this pressure acts as a source of gravity according to general relativity, in which mass, energy, stress and pressure are all sources of gravity. Quantum Fermi pressure in nuclei and degeneracy pressure in stars should measureably alter space–time, and thus provide a new test of classical general relativity in which relativistic quantum effects on matter manifest as a modification of the Newtonian gravitational field of a source mass. But the situation is subtle owing to the gravity with opposite sign from the surface tension at boundaries confining such quantum matter. We discuss the general scenario, the first quantitative empirical investigation and a successful high precision test of the equality of the active and passive gravitational masses corresponding to the quantum pressure.

scholarly journals Long-Range Scalar Forces in Five-Dimensional General Relativity

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
L. L. Williams
Keyword(s):  
General Relativity ◽  
Scalar Field ◽  
Long Range ◽  
Electric Charge ◽  
Scalar Potential ◽  
Classical Field ◽  
Electric Force ◽  
Mass Energy ◽  
Scalar Charge ◽  
Electrically Charged

We present new results regarding the long-range scalar field that emerges from the classical Kaluza unification of general relativity and electromagnetism. The Kaluza framework reproduces known physics exactly when the scalar field goes to one, so we studied perturbations of the scalar field around unity, as is done for gravity in the Newtonian limit of general relativity. A suite of interesting phenomena unknown to the Kaluza literature is revealed: planetary masses are clothed in scalar field, which contributes 25% of the mass-energy of the clothed mass; the scalar potential around a planet is positive, compared with the negative gravitational potential; at laboratory scales, the scalar charge which couples to the scalar field is quadratic in electric charge; a new length scale of physics is encountered for the static scalar field around an electrically-charged mass, L s = μ 0 Q 2 / M ; the scalar charge of elementary particles is proportional to the electric charge, making the scalar force indistinguishable from the atomic electric force. An unduly strong electrogravitic buoyancy force is predicted for electrically-charged objects in the planetary scalar field, and this calculation appears to be the first quantitative falsification of the Kaluza unification. Since the simplest classical field, a long-range scalar field, is expected in nature, and since the Kaluza scalar field is as weak as gravity, we suggest that if there is an error in this calculation, it is likely to be in the magnitude of the coupling to the scalar field, not in the existence or magnitude of the scalar field itself.

scholarly journals From General Relativity to A Simple-Harmonically Oscillating Universe, and Vice-Versa: A Review

2017 ◽  
Vol 9 (1) ◽  
pp. 86 ◽  
Author(s):  
Carmine Cataldo
Keyword(s):  
General Relativity ◽  
Cosmological Constant ◽  
Gravitational Constant ◽  
Spatial Dimension ◽  
Global Symmetry ◽  
Mass Energy ◽  
Fluid Equation ◽  
Energy Equivalence ◽  
Curvature Parameter ◽  
The Universe

In this paper two different lines of reasoning are followed in order to discuss a Universe that belongs to the so-called oscillatory class. In the first section, we start from the general writing of the first Friedmann – Lemaître equation. Taking into account mass – energy equivalence, the so-called fluid equation is immediately deduced, with the usual hypotheses of homogeneity and isotropy, once identified the evolution of the Universe with an isentropic process. Considering equal to zero the curvature parameter, and carrying out an opportune position concerning the so-called cosmological constant, we obtain an oscillating class, to which a simple-harmonically oscillating Universe evidently belongs. In the second section, we start from a simple-harmonically oscillating Universe, hypothesized globally flat and characterized by at least a further spatial dimension. Once defined the density, taking into account a global symmetry elsewhere postulated, we carry out a simple but noteworthy position concerning the gravitational constant. Then, once established the dependence between pressure and density, we deduce, by means of simple mathematical passages, the equations of Friedmann – Lemaître, without using Einstein’s Relativity.

Transfer of energy in general relativity

1970 ◽  
Vol 320 (1542) ◽  
pp. 277-287 ◽  
Keyword(s):  
General Relativity ◽  
Near Field ◽  
Equations Of Motion ◽  
Flat Space ◽  
Gravitational Energy ◽  
Mass Energy ◽  
Axially Symmetric ◽  
Surface Integral ◽  
Strong Fields ◽  
Time Sequences

This paper studies time sequences of axially symmetric static configurations which can be continuously deformed into each other. We find the restriction which characterizes those time sequences which are physically allowed. This restriction can be interpreted as the law governing the non-radiative, or near field, transfer of gravitational energy, - m = ∯ P . d S and helps to clarify the concept of mass-energy in general relativity. We consider only the regions of space surrounding a source where, for quasi-static systems, the exact, static, empty space solutions of Weyl and Levi-Civita are good approximations at all times, and exact whenever the motion stops. Our results are then valid for arbitrarily strong fields. The restriction on the time sequences can be expressed as a restriction on the time dependence of the multipole moments A l , B l (which are defined by the Weyl and Levi Civita solutions), becoming then -d/d t [ A 0 + ½ G ∑ l = 0 ∞ (2 l + 1) A l B l ] = ½ G ∑ l = 0 ∞ ( A l B l - A l B l ). The right-hand side of this expression corresponds exactly to the flux of energy across a surface, as given by Bondi’s Newtonian Poynting vector P = (1/8 π G ) ( ϕ ∇ ϕ - ϕ ∇ ϕ ). It is natural to identify A 0 + ½ G ∑ l = 0 ∞ (2 l + 1) A l B l with the total mass-energy m enclosed by the surface. m can also be expressed as a surface intergal. Our restriction was derived from the vanishing of a surface integral in much the same manner as the equations of motion are derived in post-Newtonain approximations. However, it holds in arbitrarily strong fields, whereas the usual post-Newtonian methods use in lowest order a trivial solution (flat space) and can only be used in weak fields.

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