hide
Free keywords:
General Relativity and Quantum Cosmology, gr-qc,Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO,High Energy Physics - Phenomenology, hep-ph
Abstract:
Space-based gravitational-wave detectors, such as LISA or a similar ESA-led
mission, will offer unique opportunities to test general relativity. We study
the bounds that space-based detectors could place on the graviton Compton
wavelength \lambda_g=h/(m_g c) by observing multiple inspiralling black hole
binaries. We show that while observations of individual inspirals will yield
mean bounds \lambda_g~3x10^15 km, the combined bound from observing ~50 events
in a two-year mission is about ten times better: \lambda_g~3x10^16 km
(m_g~4x10^-26 eV). The bound improves faster than the square root of the number
of observed events, because typically a few sources provide constraints as much
as three times better than the mean. This result is only mildly dependent on
details of black hole formation and detector characteristics. The bound
achievable in practice should be one order of magnitude better than this figure
(and hence almost competitive with the static, model-dependent bounds from
gravitational effects on cosmological scales), because our calculations ignore
the merger/ringdown portion of the waveform. The observation that an ensemble
of events can sensibly improve the bounds that individual binaries set on
\lambda_g applies to any theory whose deviations from general relativity are
parametrized by a set of global parameters.
