Constraining the Polarization Content of Gravitational Waves with Astrometry

Abstract

Gravitational waves perturb the paths of photons, impacting both the time-of-flight and the arrival direction of light from stars. Pulsar timing arrays can detect gravitational waves by measuring the variations in the time of flight of radio pulses, while astrometry missions such as Gaia can detect gravitational waves from the time-varying changes in the apparent position of a field of stars. Just as gravitational waves impart a characteristic correlation pattern in the arrival times of pulses from pulsars at different sky locations, the deflection of starlight is similarly correlated across the sky. Here we compute the astrometric correlation patterns for the full range of polarization states found in alternative theories of gravity, and decompose the sky-averaged correlation patterns into vector spherical harmonics. We find that the tensor and vector polarization states produce equal power in the electric- and magnetic-type vector spherical harmonics, while the scalar modes produce only electric-type correlations. Any difference in the measured electric and magnetic-type correlations would represent a clear violation of Einstein gravity. The angular correlations functions for the vector and scalar longitudinal modes show the same enhanced response at small angular separations that is familiar from pulsar timing.

arXiv comment8 pages, 6 figures

References in corpus (22)

• Observation of Gravitational Waves from a Binary Black Hole Merger
• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• The Gaia mission
• The Confrontation between General Relativity and Experiment
• Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
• GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence
• Tests of general relativity with GW150914
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Angular Power Spectrum
• Gravitational Wave Tests of General Relativity with Ground-Based Detectors and Pulsar Timing Arrays
• Model-Independent Test of General Relativity: An Extended post-Einsteinian Framework with Complete Polarization Content
• Astrometric Effects of a Stochastic Gravitational Wave Background
• Stochastic backgrounds in alternative theories of gravity: overlap reduction functions for pulsar timing arrays
• Estimating distances from parallaxes. III. Distances of two million stars in the Gaia DR1 catalogue
• A Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background
• An astrometric search method for individually resolvable gravitational wave sources with Gaia
• Analysis of astrometric catalogues with vector spherical harmonics
• First search for nontensorial gravitational waves from known pulsars
• Bounding the speed of gravity with gravitational wave observations
• Constraining alternative theories of gravity using pulsar timing arrays
• Gaia-like astrometry and gravitational waves
• Pulsar Timing Sensitivities to Gravitational Waves from Relativistic Metric Theories of Gravity
• The effect of small inter-pulsar distance variations in stochastic gravitational wave background searches with Pulsar Timing Arrays

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