Ghost-free Palatini derivative scalar-tensor theory: desingularization and the speed test
arXiv:1808.00492 · doi:10.1016/j.physletb.2019.01.061
Abstract
We disclose remarkable features of the scalar-tensor theory with the derivative coupling of the scalar field to the curvature in the Palatini formalism. Using the disformal transformations, we show that this theory is free from Otrogradski ghosts. For a special relation between two coupling constants, it is disformally dual to the Einstein gravity minimally coupled to the scalar, which opens the way to constructing several exact solutions. The disformal transformation degenerates at the boundary of the physical region, near which the properties of desingularization are revealed, illustrated by exact solutions: non-singular accelerating cosmology and a static spherically symmetric geon. We also construct the exact pp-waves of this theory propagating at the speed of light.
New references added, discussion of disformal duality extended, misprints corrected
References in corpus (12)
- GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
- Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
- Dark Energy after GW170817: dead ends and the road ahead
- Strong constraints on cosmological gravity from GW170817 and GRB 170817A
- Implications of the Neutron Star Merger GW170817 for Cosmological Scalar-Tensor Theories
- Palatini Approach to Modified Gravity: f(R) Theories and Beyond
- Mimetic gravity: a review of recent developments and applications to cosmology and astrophysics
- Palatini formulation of modified gravity with a nonminimal curvature-matter coupling
- Lovelock Gravity at the Crossroads of Palatini and Metric Formulations
- Realistic cosmological scenario with non-minimal kinetic coupling
- Dynamical Aspects of Generalized Palatini Theories of Gravity
- Disformal invariance of cosmological perturbations in a generalized class of Horndeski theories
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- On the KG-constrained general disformal transformation of the Einstein-Hilbert action
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