scholarly journals COSMOLOGICAL CONSTANT AND THE SPEED OF LIGHT

2001 ◽  
Vol 10 (01) ◽  
pp. 41-48 ◽  
Author(s):  
W. R. ESPÓSITO MIGUEL ◽  
J. G. PEREIRA
Keyword(s):  
Gravitational Field ◽  
Cosmological Constant ◽  
Electromagnetic Waves ◽  
Light Propagation ◽  
Wave Optics ◽  
Speed Of Light ◽  
Positive Cosmological Constant ◽  
Velocity Of Light ◽  
Refractive Medium ◽  
The Relationship

By exploring the relationship between the propagation of electromagnetic waves in a gravitational field and the light propagation in a refractive medium, it is shown that, in the presence of a positive cosmological constant, the velocity of light will be smaller than its special relativity value. Then, restricting again to the domain of validity of geometrical optics, the same result is obtained in the context of wave optics. It is argued that this phenomenon and the anisotropy in the velocity of light in a gravitational field are produced by the same mechanism.

A proposal for an electrical connection between the gravitational field and light

2020 ◽  
Vol 33 (3) ◽  
pp. 271-275
Author(s):  
Michael J. Curran
Keyword(s):  
Gravitational Field ◽  
Magnetic Fields ◽  
Gravitational Waves ◽  
Building Block ◽  
Electromagnetic Waves ◽  
Direct Photon ◽  
The Sun ◽  
Speed Of Light ◽  
Electrical Connection ◽  
The Relationship

Based on well-established equations, we provide evidence of an electrical connection between the gravitational field and light. Each is modeled using the inductance‐capacitance ( <mml:math display="inline"> <mml:mrow> <mml:mi>L</mml:mi> <mml:mi>C</mml:mi> </mml:mrow> </mml:math> ) circuit as the building block. A proposed direct photon force (not a pressure and not by means of a force carrier), the relationship between the speed of light and gravity, the frequency and wavelength of gravitational waves, gravitational redshift, the trajectory of planets around the sun, and equations of plane electromagnetic waves may all be expressed with the assistance of an ideal (no resistance) <mml:math display="inline"> <mml:mrow> <mml:mi>L</mml:mi> <mml:mi>C</mml:mi> </mml:mrow> </mml:math> circuit model of light. Each begins with the Planck‐Einstein relationship. Each suggests that gravity and electromagnetism interact directly through fluctuating electrical and magnetic fields from both sources. With this perspective Einstein's concept of the warping of spacetime may not be needed to explain gravitation.

The Nature of Light

2017 ◽  
Author(s):  
Frank S. Levin
Keyword(s):  
Wave Phenomenon ◽  
Electromagnetic Waves ◽  
Speed Of Light ◽  
Particle Theory ◽  
Christiaan Huygens ◽  
Slit Experiment

Chapter 2 reviews answers to the question of what is light, starting with the ancient Greeks and ending in 1900 with the wave concept of Maxwell’s electrodynamics. For some ancient Greeks, light consisted of atoms emitted from surface of the object, whereas for others it was fire that either entered into or was emitted by eyes, although the latter possibility was effectively eliminated around the year 1000. Competing proposals well after then were that light is either a wave phenomenon or consists of particles, with Isaac Newton’s corpuscular (particle) theory prevailing by the end of the 1600s over the wave concept championed by Christiaan Huygens, who published the first estimate of the speed of light. In the early 1800s, Thomas Young’s two-slit experiment proved that light was a wave, a concept codified and firmly grounded through Maxwell’s theory of electromagnetic waves.

scholarly journals Neutral signature gauged supergravity solutions

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
J. Gutowski ◽  
W. A. Sabra
Keyword(s):  
Cosmological Constant ◽  
Geometric Structure ◽  
Base Space ◽  
Killing Spinor ◽  
Positive Cosmological Constant ◽  
3 Dimensional

Abstract We classify all supersymmetric solutions of minimal D = 4 gauged supergravity with (2) signature and a positive cosmological constant which admit exactly one Killing spinor. This classification produces a geometric structure which is more general than that found for previous classifications of N = 2 supersymmetric solutions of this theory. We illustrate how the N = 2 solutions which consist of a fibration over a 3-dimensional Lorentzian Gauduchon-Tod base space can be written in terms of this more generic geometric structure.

scholarly journals TIME, VACUUM ENERGY, AND THE COSMOLOGICAL CONSTANT

2009 ◽  
Vol 18 (14) ◽  
pp. 2265-2268 ◽  
Author(s):  
VIQAR HUSAIN
Keyword(s):  
Quantum Gravity ◽  
Cosmological Constant ◽  
Vacuum Energy ◽  
Cosmological Constant Problem ◽  
Problem Of Time ◽  
The Relationship

We describe a link between the cosmological constant problem and the problem of time in quantum gravity. This arises from examining the relationship between the cosmological constant and vacuum energy in light of nonperturbative formulations of quantum gravity.

scholarly journals Relationship between Bondi–Sachs quantities and source of gravitational radiation in asymptotically de Sitter spacetime

2018 ◽  
Vol 27 (04) ◽  
pp. 1850046 ◽  
Author(s):  
Xiaokai He ◽  
Jiliang Jing ◽  
Zhoujian Cao
Keyword(s):  
Cosmological Constant ◽  
Gravitational Wave ◽  
Gravitational Radiation ◽  
The Other ◽  
Perturbation Approach ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Positive Cosmological Constant ◽  
Sitter Spacetime ◽  
Explicit Expressions

Gravitational radiation plays an important role in astrophysics. Based on the fact that our universe is expanding, the gravitational radiation when a positive cosmological constant is presented has been studied along with two different ways recently, one is the Bondi–Sachs (BS) framework in which the result is shown by BS quantities in the asymptotic null structure, the other is the perturbation approach in which the result is presented by the quadrupoles of source. Therefore, it is worth to interpret the quantities in asymptotic null structure in terms of the information of the source. In this paper, we investigate this problem and find the explicit expressions of BS quantities in terms of the quadrupoles of source in asymptotically de Sitter spacetime. We also estimate how far away the source is, the cosmological constant may affect the detection of the gravitational wave.

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