How Fabulous Is Fab 5 Cosmology?

Abstract

Extended gravity origins for cosmic acceleration can solve some fine tuning issues and have useful characteristics, but generally have little to say regarding the cosmological constant problem. Fab 5 gravity can be ghost free and stable, have attractor solutions in the past and future, and possess self tuning that solves the original cosmological constant problem. Here we show however it does not possess all these qualities at the same time. We also demonstrate that the self tuning is so powerful that it not only cancels the cosmological constant but also all other energy density, and we derive the scalings of its approach to a renormalized de Sitter cosmology. While this strong cancellation is bad for the late universe, it greatly eases early universe inflation.

6 pages, 2 figures; v2 minor change to match published version

References in corpus (7)

• Covariant Galileon
• Generalized Galileons: All scalar models whose curved background extensions maintain second-order field equations and stress tensors
• Screening Modifications of Gravity through Disformally Coupled Fields
• Kinetic k-essence and Quintessence
• Fab Four: When John and George play gravitation and cosmology
• Fab 5: Noncanonical Kinetic Gravity, Self Tuning, and Cosmic Acceleration
• Derivative Chameleons

Cited by in corpus (18)

• Beyond the Cosmological Standard Model
• Testing General Relativity in Cosmology
• Stability of a black hole and the speed of gravity waves within self-tuning cosmological models
• Horndeski theories self-tuning to a de Sitter vacuum
• Cosmological self-tuning and local solutions in generalized Horndeski theories
• The Well-Tempered Cosmological Constant
• Superradiant Instabilities in a Class of Scalar-Tensor Horndeski Theory
• Self Tuning Scalar Fields in Spherically Symmetric Spacetimes
• Well-Tempered Minkowski Solutions in Teleparallel Horndeski Theory
• Generation of primordial black holes from an inflation model with modified dispersion relation
• Well-Tempered Cosmology
• Attracted to de Sitter: cosmology of the linear Horndeski models
• The Well-Tempered Cosmological Constant: The Horndeski Variations
• The Well-Tempered Cosmological Constant: Fugue in B${}^{♭}$
• Generalised scalar-tensor theories and self-tuning
• Fab-Four cosmography to tackle the Hubble tension
• Implications of the primordial anisotropy for a scalar field with non-minimal kinetic coupling
• Non-minimal kinetic coupled gravity: inflation on the Warped DGP brane