The Swampland and Screened Modified Gravity

Abstract

We consider the implications of the swampland conjectures on scalar-tensor theories defined in the Einstein frame in which the scalar interaction is screened. We show that chameleon models are not in the swampland provided the coupling to matter is larger than unity and the mass of the scalar field is much larger than the Hubble rate. We apply these conditions to the inverse power law chameleon and the symmetron. We then focus on the dilaton of string theory in the strong coupling limit, as defined in the string frame. We show that solar system tests of gravity imply that viable dilaton models are not in the swampland. In the future of the Universe, if the low energy description with a single scalar is still valid and the coupling to matter remains finite, we find that the scalar field energy density must vanish for models with the chameleon and symmetron mechanisms. Hence in these models dark energy is only a transient phenomenon. This is not the case for the strongly coupled dilaton, which keeps evolving slowly, leading to a quasi de Sitter space-time.

24 pages

References in corpus (44)

• Chameleon Cosmology
• On the Geometry of the String Landscape and the Swampland
• The Swampland: Introduction and Review
• Distance and de Sitter Conjectures on the Swampland
• On the Cosmological Implications of the String Swampland
• Detecting Dark Energy in Orbit -- the Cosmological Chameleon
• Quintessence as a run-away dilaton
• De Sitter Space and the Swampland
• Runaway dilaton and equivalence principle violations
• Symmetron Cosmology
• The landscape, the swampland and the era of precision cosmology
• The Dilaton and Modified Gravity
• A Unified Description of Screened Modified Gravity
• The string swampland constraints require multi-field inflation
• De Sitter vs Quintessence in String Theory
• Dark Energy Condensation
• Dark Energy in the Swampland
• The zoo plot meets the swampland: mutual (in)consistency of single-field inflation, string conjectures, and cosmological data
• A note on Inflation and the Swampland
• Improved BBN Constraints on the Variation of the Gravitational Constant
• de Sitter Swampland, $H_0$ tension & observation
• Eternal Inflation and the Refined Swampland Conjecture
• Chameleons with Field Dependent Couplings
• Searching for dark matter - dark energy interactions: going beyond the conformal case
• Modified Gravity Tomography
• Avoiding the string swampland in single-field inflation: Excited initial states
• Runaway Quintessence, Out of the Swampland
• The Swampland, Quintessence and the Vacuum Energy
• Steep Eternal Inflation and the Swampland
• An equivalence principle for scalar forces
• Chaotic inflation on the brane and the Swampland Criteria
• Linear Growth of Structure in the Symmetron Model
• Swampland conjecture in $f(R)$ gravity by the Noether Symmetry Approach
• Towards a UV Completion for Chameleon Scalar Theories
• Chameleons in the Early Universe: Kicks, Rebounds, and Particle Production
• The $F$-term Problem and other Challenges of Stringy Quintessence
• Dark Energy, the Swampland and the Equivalence Principle
• Strongly Coupled Quintessence
• Moduli Fields as Quintessence and the Chameleon
• Thermal Dark Energy
• Quantum Fine-Tuning in Stringy Quintessence Models
• Finding structure in the dark: coupled dark energy, weak lensing, and the mildly nonlinear regime
• Forays into the dark side of the swamp
• Dark Energy in the Swampland II

Cited by in corpus (8)

• Direct detection of dark energy: the XENON1T excess and future prospects
• Dark energy interactions near the galactic centre
• Dilaton Solutions for Laboratory Constraints and Lunar Laser Ranging
• Cosmology at the top of the ${\alpha }^{\prime }$ tower
• Imprints of screened dark energy on nonlocal quantum correlations
• Constraints on Late Time Violations of the Equivalence Principle in the Dark Sector
• Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the string-theoretical Swampland Programme
• Dynamical Chameleon Neutron Stars: stability, radial oscillations and scalar radiation in spherical symmetry