Constraints on Einstein-ther theory and Horava gravity from binary pulsar observations

Kent Yagi, Diego Blas, Enrico Barausse, Nicolás Yunes

Research output: Contribution to journalArticlepeer-review

165 Citations (Scopus)


Binary pulsars are ideal to test the foundations of general relativity, such as Lorentz symmetry, which requires that experiments produce the same results in all free-falling (i.e. inertial) frames. We here break this symmetry in the gravitational sector by specifying a preferred time direction, and thus a preferred frame, at each spacetime point. We then examine the consequences of this gravitational Lorentz symmetry breaking in the orbital evolution of binary pulsars, focusing on the dissipative effects. We find that Lorentz symmetry breaking modifies these effects, and thus the orbital dynamics, in two different ways. First, it generically causes the emission of dipolar radiation, which makes the orbital separation decrease faster than in general relativity. Second, the quadrupole component of the emission is also modified. The orbital evolution depends critically on the sensitivities of the stars, which measure how their binding energies depend on the motion relative to the preferred frame. We calculate the sensitivities numerically and compute the predicted orbital decay rate of binary pulsars in Lorentz-violating gravity. By testing these predictions against observations, we place very stringent constraints on gravitational Lorentz violation.
Original languageEnglish
Pages (from-to)084067
Number of pages1
JournalPhysical Review D (Particles, Fields, Gravitation and Cosmology)
Early online date1 Apr 2014
Publication statusPublished - 24 Apr 2014


  • 04.50.Kd, 04.80.Cc, 04.30.-w, 97.60.Jd, Modified theories of gravity, Experimental tests of gravitational theories, Gravitational waves: theory, Neutron stars, General Relativity and Quantum Cosmology, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology, High Energy Physics - Theory


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