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arXiv · 2009.01723

The Well-Tempered Cosmological Constant: Fugue in B$^\flat$

Stephen Appleby·Eric V. Linder
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Abstract

Zero point fluctuations of quantum fields should generate a large cosmological constant energy density in any spacetime. How then can we have anything other than de Sitter space without fine tuning? Well tempering -- dynamical cancellation of the cosmological constant using degeneracy within the field equations -- can replace a large cosmological constant with a much lower energy state. Here we give an explicit mechanism to obtain a Minkowski solution, replacing the cosmological constant with zero, and testing its attractor nature and persistence through a vacuum phase transition. We derive the general conditions that Horndeski scalar-tensor gravity must possess, and evolve in a fugue of functions, to deliver nothing and make the universe be flat.

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Stephen Appleby, Eric V. Linder. 2020-09-03. The Well-Tempered Cosmological Constant: Fugue in B$^\flat$. https://doi.org/10.1088/1475-7516/2020/12/037

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