Eanna E. Flanagan

Measuring gravitational waves from binary black hole coalescences. I. Signal to noise for inspiral, merger, and ringdown

We estimate the expected signal-to-noise ratios (SNRs) from the three phases (inspiral, merger, and ringdown) of coalescing binary black holes (BBHs) for initial and advanced ground-based interferometers (LIGO-VIRGO) and for the space-based interferometer LISA. Ground-based interferometers can do moderate SNR (a few tens), moderate accuracy studies of BBH coalescences in the mass range of a few to about 2000 solar masses; LISA can do high SNR (of order 104), high accuracy studies in the mass range of about 105–108 solar masses. BBHs might well be the first sources detected by LIGO-VIRGO: they are visible to much larger distances—up to 500 Mpc by initial interferometers—than coalescing neutron star binaries (heretofore regarded as the “bread and butter” workhorse source for LIGO-VIRGO, visible to about 30 Mpc by initial interferometers). Low-mass BBHs (up to 50M⊙ for initial LIGO interferometers, 100M⊙ for advanced, 106M⊙ for LISA) are best searched for via their well-understood inspiral waves; higher mass BBHs must be searched for via their poorly understood merger waves and/or their well-understood ringdown waves. A matched filtering search for massive BBHs based on ringdown waves should be capable of finding BBHs in the mass range of about 100M⊙–700M⊙ out to ∼200 Mpc for initial LIGO interferometers, and in the mass range of ∼200M⊙ to ∼3000M⊙ out to about z=1 for advanced interferometers. The required number of templates is of the order of 6000 or less. Searches based on merger waves could increase the number of detected massive BBHs by a factor of the order of 10 over those found from inspiral and ringdown waves, without detailed knowledge of the waveform shapes, using a noise monitoring search algorithm which we describe. A full set of merger templates from numerical relativity simulations could further increase the number of detected BBHs by an additional factor of up to ∼4.

The conformal frame freedom in theories of gravitation

It has frequently been claimed in the literature that the classical physical predictions of scalar–tensor theories of gravity depend on the conformal frame in which the theory is formulated. We argue that this claim is false, and that all classical physical predictions are conformal-frame invariants. We also respond to criticisms by Vollick (2003 Preprint gr-qc/0312041), in which this issue arises, of our recent analysis of the Palatini form of 1/R gravity.

Constraining neutron-star tidal Love numbers with gravitational-wave detectors

Ground-based gravitational wave detectors may be able to constrain the nuclear equation of state using the early, low frequency portion of the signal of detected neutron star--neutron star inspirals. In this early adiabatic regime, the influence of a neutron stars internal structure on the phase of the waveform depends only on a single parameter

Palatini form of 1/R gravity.

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Cosmological expansion in the Randall-Sundrum brane world scenario

of the star related to its tidal Love number, namely, the ratio of the induced quadrupole moment to the perturbing tidal gravitational field. We analyze the information obtainable from gravitational wave frequencies smaller than a cutoff frequency of 400 Hz, where corrections to the internal-structure signal are less than 10%. For an inspiral of two nonspinning

Dark energy or modified gravity? An effective field theory approach

1.4{M}_{\ensuremath{\bigodot}}

Constraining Interactions in Cosmology's Dark Sector

neutron stars at a distance of 50 Megaparsecs, LIGO II detectors will be able to constrain

Higher-order gravity theories and scalar?tensor theories

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Mimicking dark energy with Lemaitre-Tolman-Bondi models: Weak central singularities and critical points

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Sensitivity of the Laser Interferometer Gravitational Wave Observatory to a stochastic background, and its dependence on the detector orientations

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