2018/04/02 by Deyan P. Mihaylov, Christopher J. Moore, Jonathan R. Gair +5 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Astrometry #Astronomy #Astrophysics #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #Gravitational field #Gravitational redshift #Gravitational wave #Gravitational wave background #Gravitational-wave astronomy #Gravitational-wave observatory #Physics #Polarization (electrochemistry) #Pulsar #Pulsars and Gravitational Waves Research #Sky #Stars #gr-qc
paper · pdf · doi:10.1103/physrevd.97.124058
published as Phys. Rev. D 97, 124058 (2018) · 14 pages, 12 figures
arxiv created 2018/04/02 · openalex created_date 2018/04/13 · openalex publication_date 2018/06/22 · arxiv updated 2018/06/27 · openalex updated_date 2026/08/05
The Gaia mission offers a new opportunity to search for the low-frequency gravitational wave background using astrometric measurements. In this paper, the astrometric effect of gravitational waves is reviewed, with a particular focus on the effect of non-Einsteinian gravitational wave polarizations. A stochastic gravitational wave background generates a correlated vector field of astrometric deflections on the sky. A convenient decomposition for the correlation matrix is introduced, enabling it to be calculated for all possible gravitational wave polarizations and compared to the redshift correlations from the pulsar-timing literature; in the case of a general relativity background of transverse traceless gravitational waves, this also allows us to identify an astrometric analog of the famous Hellings-Downs curve. Finally, the cross correlation between the redshift and astrometric signal is also calculated; this may form the basis for future joint pulsar-timing and astrometry searches for arbitrarily polarized gravitational wave backgrounds.