Earth rotation and time-domain reconstruction of polarization states for continuous gravitational waves from a known pulsar

Abstract

We consider effects of the Earth rotation on antenna patterns of a ground-based gravitational wave (GW) detector in a general metric theory that allows at most six polarization states (two spin-0, two spin-1 and two spin-2) in a four-dimensional spacetime. By defining the cyclically averaged antenna matrix for continuous GWs from a known pulsar, we show that waveforms for each polarization state can be uniquely reconstructed in time domain from a given set of the strain outputs at a single detector. Constraining the propagation speed of extra polarization modes, if they coexist with the transverse-traceless modes, is also discussed. We examine also possible effects due to the length-of-day modulation as well as a secular change in the pulsar spin period.