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arXiv · 1804.00660

Astrometric Effects of Gravitational Wave Backgrounds with non-Einsteinian Polarizations

Deyan P. Mihaylov·Christopher J. Moore·Jonathan R. Gair·Anthony Lasenby·Gerard Gilmore
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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 GR 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.

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Deyan P. Mihaylov, Christopher J. Moore, Jonathan R. Gair, Anthony Lasenby, Gerard Gilmore. 2018-04-02. Astrometric Effects of Gravitational Wave Backgrounds with non-Einsteinian Polarizations. https://doi.org/10.1103/physrevd.97.124058

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