The Well-Tempered Cosmological Constant

Abstract

Self tuning is one of the few methods for dynamically cancelling a large cosmological constant and yet giving an accelerating universe. Its drawback is that it tends to screen all sources of energy density, including matter. We develop a model that tempers the self tuning so the dynamical scalar field still cancels an arbitrary cosmological constant, including the vacuum energy through any high energy phase transitions, without affecting the matter fields. The scalar-tensor gravitational action is simple, related to cubic Horndeski gravity, with a nonlinear derivative interaction plus a tadpole term. Applying shift symmetry and using the property of degeneracy of the field equations we find families of functions that admit de Sitter solutions with expansion rates that are independent of the magnitude of the cosmological constant and preserve radiation and matter dominated phases. That is, the method can deliver a standard cosmic history including current acceleration, despite the presence of a Planck scale cosmological constant.

19 pages, 4 figures

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Cited by in corpus (37)

• The Novel Probes Project -- Tests of Gravity on Astrophysical Scales
• Black Holes in $f(T,B)$ Gravity: Exact and Perturbed Solutions
• Classification of Teleparallel Horndeski Cosmology via Noether Symmetries
• Well-tempered teleparallel Horndeski cosmology: a teleparallel variation to the cosmological constant problem
• Well-Tempered Minkowski Solutions in Teleparallel Horndeski Theory
• General Effective Field Theory of Teleparallel Gravity
• Noether Symmetry Approach in Scalar-Torsion $f(T,\varphi )$ Gravity
• Ghost and Laplacian Instabilities in the Teleparallel Horndeski Gravity
• Well-Tempered Cosmology
• Proca theory of four-dimensional regularized Gauss-Bonnet gravity and black holes with primary hair
• Noether Symmetries in $f(T,T_G)$ Cosmology
• A Graceful Exit for the Cosmological Constant Damping Scenario
• Tracing cosmic evolution through Weyl-Type f(Q,T) gravity model: theoretical analysis and observational validation
• The Well-Tempered Cosmological Constant: The Horndeski Variations
• A minimal self tuning model to solve the cosmological constant problem
• No Run Gravity
• Tailoring cosmologies in cubic shift-symmetric Horndeski gravity
• Massless minimal quantum scalar field with an asymmetric self interaction in de Sitter spacetime
• The Well-Tempered Cosmological Constant: Fugue in B${}^{♭}$
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• Stealth black hole perturbations in kinetic gravity braiding
• Screening and degenerate kinetic self-acceleration from the nonlinear freedom of reconstructed Horndeski theories
• Cosmological cancellation of the vacuum energy density
• An Expansion of Well Tempered Gravity
• Tadpole Cosmology: Self Tuning Without Degeneracy
• Self-tuning of the cosmological constant in brane-worlds with $P(X,\varphi )$
• Fab-Four cosmography to tackle the Hubble tension
• Resummation of local and non-local scalar self energies via the Schwinger-Dyson equation in de Sitter spacetime
• The nonlinear anisotropic model of the Universe with the linear potential
• Studying the variation of fundamental constants at the Cosmic Ray Extremely Distributed Observatory
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