Item

Abstract

We derive the parameter-space metric of the multi-detector F-statistic, which is the optimal detection statistic for continuous gravitational waves in stationary Gaussian noise. We find that there is a family of F-statistic metrics, parametrized by the (unknown) amplitude parameters. We explicitly derive the maximal mismatch-range of this metric family, and we introduce a corresponding "average" F-metric. We show that the multi-detector metric consists of noise-weighted averages of single-detector contributions, which implies that the number of templates required to cover the parameter space does not scale with the number of detectors. Contrary to using a longer observation time, combining more detectors (of similar sensitivity) is therefore the computationally cheapest way to improve the sensitivity of a coherent wide-parameter search for continuous gravitational waves. We explicitly compute the F-statistic metric (family) for signals from isolated spinning neutron stars, and we evaluate the quality of different metric approximations in a Monte-Carlo study. We also compare the metric predictions to the measured mismatches and identify two regimes in which the metric is not a good description of the parameter-space structure. Comment of the Author: Erratum-ibid. D75 (2007) 069901