Gravitational wave defocussing in quadratic gravity

Gravitational-wave probe of effective quantum gravity

Testing Gravity with Gravitational Wave Source Counts

We show that the gravitational wave source counts distribution can test how gravitational radiation propagates on cosmological scales. This test does not require obtaining redshifts for the sources. If the signal-to-noise ratio (SNR, ρ) from a gravitational wave source is proportional to the strain then it falls as R−1, thus we expect the source counts to follow dN/dρ ∝ ρ−4. However, if gravita...

Human gravity-gradient noise in interferometric gravitational-wave detectors

Among all forms of routine human activity, the one which produces the strongest gravity-gradient noise in interferometric gravitational-wave detectors ~e.g. LIGO! is the beginning and end of weight transfer from one foot to the other during walking. The beginning and end of weight transfer entail sharp changes ~time scale t;20 msec! in the horizontal jerk ~first time derivative of acceleration!...

Seismic gravity-gradient noise in interferometric gravitational-wave detectors

When ambient seismic waves pass near and under an interferometric gravitational-wave detector, they induce density perturbations in the Earth, which in turn produce fluctuating gravitational forces on the interferometer’s test masses. These forces mimic a stochastic background of gravitational waves and thus constitute a noise source. This seismic gravity-gradient noise has been estimated and d...

Gravitational-wave versus binary-pulsar tests of strong-field gravity

Binary systems comprising at least one neutron star contain strong gravitational field regions and thereby provide a testing ground for strong-field gravity. Two types of data can be used to test the law of gravity in compact binaries: binary pulsar observations, or forthcoming gravitational-wave observations of inspiralling binaries. We compare the probing power of these two types of observati...