Gravitation-Wave Emission in Shift-Symmetric Horndeski Theories

Enrico Barausse (1) , Kent Yagi

1 IAP - Institut d'Astrophysique de Paris

Gravity theories beyond general relativity typically predict dipolar gravitational emission by compact-star binaries. This emission is sourced by "sensitivity" parameters depending on the stellar compactness. We introduce a general formalism to calculate these parameters, and show that in shift-symmetric Horndeski theories stellar sensitivities and dipolar radiation vanish, provided that the binary's dynamics is perturbative (i.e., the post-Newtonian formalism is applicable) and cosmological-expansion effects can be neglected. This allows one to reproduce the binary-pulsar-observed orbital decay.

Mots clés: 04.30.-w; 04.25.-g; 04.80.Cc; Gravitational waves: theory; Approximation methods; equations of motion; Experimental tests of gravitational theories; General Relativity and Quantum Cosmology; Astrophysics - Cosmology and Nongalactic Astrophysics; High Energy Physics - Theory

Domaines: Planète et Univers [physics]

Enrico Barausse, Kent Yagi. Gravitation-Wave Emission in Shift-Symmetric Horndeski Theories. Physical Review Letters, 2015, 115, ⟨10.1103/PhysRevLett.115.211105⟩. ⟨insu-03644691⟩