Astrometric effects of gravitational wave backgrounds with non-Einsteinian polarizations


Type
Article
Change log
Authors
Mihaylov, DP 
Moore, CJ 
Gair, JR 
Abstract

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.

Description
Keywords
gr-qc, gr-qc
Journal Title
Physical Review D - Particles, Fields, Gravitation and Cosmology
Conference Name
Journal ISSN
1550-7998
2470-0029
Volume Title
97
Publisher
American Physical Society
Sponsorship
European Research Council (646597)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (690904)
D. M. is funded by the STFC. C. M. acknowledges financial support provided under the European Union’s H2020 ERC Consolidator Grant “Matter and strong-field gravity: New frontiers in Einsteins theory” grant agreement no. MaGRaTh646597. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 690904 and C. M. would like to acknowledge networking support by the COST Action CA16104.