Dark Energy in light of Multi-Messenger Gravitational-Wave astronomy
Résumé
Gravitational waves (GWs) provide a new tool to probe the nature of dark energy (DE) and the fundamental properties of gravity. We review the different ways in which GWs can be used to test theories of gravity and cosmology, emphasizing models for late-time cosmic acceleration. Lagrangian-based gravitational theories beyond general relativity (GR) are classified into those breaking fundamental assumptions, containing additional fields and massive graviton(s). In addition to Lagrangian based theories we present the effective theory of DE and the μ-Σ parametrization as general descriptions of cosmological gravity. Multi-messenger GW detections can be used to measure the cosmological expansion (standard sirens), providing an independent test of the DE equation of state and measuring the Hubble parameter. Several key tests of gravity involve the cosmological propagation of GWs, including anomalous GW speed, massive graviton excitations, Lorentz violating dispersion relation, modified GW luminosity distance and additional polarizations, which may also cause GW oscillations. We summarize present constraints and their impact on DE models, including those arising from the binary neutron star merger GW170817. Upgrades of LIGO-Virgo detectors to design sensitivity and the next generation facilities such as LISA or Einstein Telescope will significantly improve these constraints in the next two decades.
Mots clés
Dark energy (DE)
Gravitation
gravitational wave astronomy
Cosmology - Theory
Dark energy and cosmology
Multi-messenger astronomy
Multi-messenger astrophysics
modified gravity
gravitation: massive
graviton: massive
dark energy: equation of state
expansion: acceleration
graviton: excited state
neutron star: binary
violation: Lorentz
gravitational radiation
gravitational radiation detector
gravitational radiation: emission
gravitational radiation: direct detection
dispersion relation
Einstein Telescope
general relativity
Hubble constant
detector: sensitivity
detector: upgrade
LISA