Classical Cancellation of the Cosmological Constant Re-Considered

Abstract

We revisit a scenario in which the cosmological constant is cancelled by the potential energy of a slowly evolving scalar field, or "cosmon". The cosmon's evolution is tied to the cosmological constant by a feedback mechanism. This feedback is achieved by an unconventional coupling of the cosmon field to the Ricci curvature scalar. The solutions show that the effective cosmological constant evolves approximately as $t^{-2}$ and remains always of the same order as the density of ordinary matter and radiation. Newton's constant varies on cosmological time scales, with ${\dot{G}}_N/G_N\ll 1/t$. $G_N$ could have been somewhat different, and possibly smaller, at the time of Big Bang nucleosynthesis.

18 pages, 1 figure; references added, corrected 2nd last paragraph of Sec 2

References in corpus (2)

• A Sudden Gravitational Transition
• Clifford Space as a Generalization of Spacetime: Prospects for QFT of Point Particles and Strings

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