Self-accelerating universe in scalar-tensor theories after GW170817

2017/12/31 by Marco Crisostomi, K. Koyama, Kazuya Koyama
Physics and Astronomy · #Astrophysics #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark matter #De Sitter universe #Gamma-ray bursts and supernovae #Gravitation #Gravitational wave #Neutron star #Physics #Pulsars and Gravitational Waves Research #Quantum mechanics #Scalar (mathematics) #Spacetime #Tensor (intrinsic definition) #Theoretical physics #Universe #astro-ph.CO #gr-qc #hep-th

paper · pdf · doi:10.1103/physrevd.97.084004

published as Phys. Rev. D 97, 084004 (2018) · 15 pages, 4 figures, references added, typos corrected, published version

openalex publication_date 2018/04/03 · arxiv created 2018/04/05 · arxiv updated 2018/04/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

The recent simultaneous detection of gravitational waves and a gamma-ray burst from a neutron star merger significantly shrank the space of viable scalar-tensor theories by demanding that the speed of gravity is equal to that of light. The survived theories belong to the class of degenerate higher order scalar-tensor theories. We study whether these theories are suitable as dark energy candidates. We find scaling solutions in the matter dominated universe that lead to de Sitter solutions at late times without the cosmological constant, realizing self-acceleration. We evaluate quasistatic perturbations around self-accelerating solutions and show that the stringent constraints coming from astrophysical objects and gravitational waves can be satisfied, leaving interesting possibilities to test these theories by cosmological observations.

Citations

• Vainshtein screening in a cosmological background in the most general second-order scalar-tensor theory
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• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
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• Multi-messenger Observations of a Binary Neutron Star Merger
• Dark Energy after GW170817: dead ends and the road ahead
• Covariant Galileon