# Cosmologies with varying light speed

@article{Barrow1999CosmologiesWV,
title={Cosmologies with varying light speed},
author={John D. Barrow},
journal={Physical Review D},
year={1999},
volume={59},
pages={043515}
}
• J. Barrow
• Published 2 November 1998
• Physics
• Physical Review D
We analyse a generalisation of general relativity that incorporates a cosmic time-variation of the velocity of light in vacuum, $c,$ and the Newtonian gravitation 'constant', $G,$ proposed by Albrecht and Maguejo. We find exact solutions for Friedmann universes and determine the rate of variation of $c$ required to solve the flatness and classical cosmological constant problems. Potential problems with this approach to the resolution of the flatness and classical cosmological constant problems…
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## References

SHOWING 1-2 OF 2 REFERENCES
A Time varying speed of light as a solution to cosmological puzzles
• Physics
• 1999
We consider the cosmological implications of light travelling faster in the early Universe. We propose a prescription for deriving corrections to the cosmological evolution equations while the speed
Varying-α theories and solutions to the cosmological problems
• Physics
• 1998
Abstract If the fine structure constant α = e 2 /(ℏ c ) were to change, then a number of interpretations would be possible, attributing this change either to variations in the electron charge, the