Hubble's constant from gravitational wave observations

Gravitational wave observations offer a uniquely accurate method for determining Hubble's constant. To determine Hubble's constant, four interferometers must see an event. The good signal-to-noise ratio then permits its position to be determined to typically +-3 . on the sky. If the event is accompanied by a detectable optical counterpart, then the redshift of its host galaxy will give H/sub o/ to a few percent. If events are not optically visible, a statistical method based upon galaxy clustering could still determine H/sub o/ to a few percent after about 10 events. Best estimates suggest an event rate of about 3 per annum. Within a few years after the detectors are working (mid 1990s), therefore, the authors should have a very accurate value of H/sub o/. Because the model is simply the Newtonian two-body system, and tidal and post-Newtonian corrections are negligible, the method is essentially free of systematic errors. It should give a value of H/sub o/ that is more reliable than any other proposed method