Spherical Cows in the Sky with Fab Four

Abstract

We explore spherically symmetric static solutions in a subclass of unitary scalar-tensor theories of gravity, called the `Fab Four' models. The weak field large distance solutions may be phenomenologically viable, but only if the Gauss-Bonnet term is negligible. Only in this limit will the Vainshtein mechanism work consistently. Further, classical constraints and unitarity bounds constrain the models quite tightly. Nevertheless, in the limits where the range of individual terms at large scales is respectively Kinetic Braiding, Horndeski, and Gauss-Bonnet, the horizon scale effects may occur while the theory satisfies Solar system constraints and, marginally, unitarity bounds. On the other hand, to bring the cutoff down to below a millimeter constrains all the couplings scales such that `Fab Fours' can't be heard outside of the Solar system.

15 pages, LaTeX

References in corpus (10)

• Resummation of Massive Gravity
• Causality, Analyticity and an IR Obstruction to UV Completion
• Generalized Galileons: All scalar models whose curved background extensions maintain second-order field equations and stress tensors
• Black holes with non-minimal derivative coupling
• Equivalence Principle Implications of Modified Gravity Models
• The recovery of General Relativity in massive gravity via the Vainshtein mechanism
• Equivalence Principle Violation in Vainshtein Screened Two-Body Systems
• Fab 5: Noncanonical Kinetic Gravity, Self Tuning, and Cosmic Acceleration
• Strong Coupling and Bounds on the Graviton Mass in Massive Gravity
• Non Pauli-Fierz Massive Gravitons

Cited by in corpus (11)

• Beyond the Cosmological Standard Model
• Lectures on the Cosmological Constant Problem
• Reheating in Gauss-Bonnet-coupled inflation
• The Well-Tempered Cosmological Constant
• Holographic self-tuning of the cosmological constant
• The Parametrized Post-Newtonian-Vainshteinian Formalism
• On Lovelock galileons and black holes
• Self Tuning Scalar Fields in Spherically Symmetric Spacetimes
• The Well-Tempered Cosmological Constant: Fugue in B${}^{♭}$
• Tadpole Cosmology: Self Tuning Without Degeneracy
• Tadpole Cosmology: Milne Solution as a Cosmological Constant Hideout