Probing Gravitational Waves from Pulsars in Brans-Dicke Theory

This paper comprises the theoretical background for the data analysis of gravitational waves (GWs) from spinning neutron stars in Brans-Dicke (BD) theory. Einstein's general theory of relativity (GR) predicts only two tensor polarization states, but a generic metric theory of gravity can also possess scalar and vector polarization states. The BD theory attempts to modify the GR by varying gravitational constant G, and it has three polarization states. The first two states are the same as in GR, and the third one is scalar polarization. We derive the response of a laser interferometric detector to the GW signal from a spinning neutron star in BD theory. We obtain a statistic based on the maximum likelihood principle to identify the signal in BD theory in the detector's noise. This statistic generalizes the well known F-statistic used in the case of GR. We perform Monte Carlo simulations in Gaussian noise to test the detectability of the signal and the accuracy of estimation of its parameters.

Automated summary

This paper presents the theoretical background for analyzing gravitational waves from spinning neutron stars in Brans-Dicke theory, which aims to modify general relativity by varying gravitational constant G and has three polarization states. The response of a laser interferometric detector to the GW signal in BD theory is derived, and a statistic based on the maximum likelihood principle is obtained to identify the signal in detector's noise. Monte Carlo simulations in Gaussian noise are performed to test the detectability of the signal and the accuracy of estimation of its parameters.