Targeted search for the kinematic dipole of the gravitational-wave background

Abstract

There is growing interest in using current and future gravitational-wave interferometers to search for anisotropies in the gravitational-wave background. One guaranteed anisotropic signal is the kinematic dipole induced by our peculiar motion with respect to the cosmic rest frame, as measured in other full-sky observables such as the cosmic microwave background. Our prior knowledge of the amplitude and direction of this dipole is not explicitly accounted for in existing searches by LIGO/Virgo/KAGRA, but could provide crucial information to help disentangle the sources which contribute to the gravitational-wave background. Here we develop a targeted search pipeline which uses this prior knowledge to enable unbiased and minimum-variance inference of the dipole magnitude. Our search generalises existing methods to allow for a time-dependent signal model, which captures the annual modulation of the dipole due to the Earth's orbit. We validate our pipeline on mock data, demonstrating that neglecting this time dependence can bias the inferred dipole by as much as $\sim 10\%$. We then run our analysis on the full LIGO/Virgo O1+O2+O3 dataset, obtaining upper limits on the dipole amplitude that are consistent with existing anisotropic search results.

12 pages, 3 figures, matches version published in PRD

References in corpus (8)

• Directional limits on persistent gravitational waves from Advanced LIGO's first observing run
• Search for anisotropic gravitational-wave backgrounds using data from Advanced LIGO and Advanced Virgo's first three observing runs
• Correlated noise in networks of gravitational-wave detectors: subtraction and mitigation
• Implications for First-Order Cosmological Phase Transitions from the Third LIGO-Virgo Observing Run
• CLASS_GWB: robust modeling of the astrophysical gravitational wave background anisotropies
• Search for a scalar induced stochastic gravitational wave background in the third LIGO-Virgo observing run
• Measuring neutron-star ellipticity with measurements of the stochastic gravitational-wave background
• Doppler boosting the stochastic gravitational wave background

Cited by in corpus (10)

• The Science of the Einstein Telescope
• Circular Polarization of the Astrophysical Gravitational Wave Background
• Measuring kinematic anisotropies with pulsar timing arrays
• Measurement of the Cross-Correlation Angular Power Spectrum Between the Stochastic Gravitational Wave Background and Galaxy Over-Density
• On the response of the Einstein Telescope to Doppler anisotropies
• Bayesian parameter estimation for targeted anisotropic gravitational-wave background
• Angular power spectra of anisotropic stochastic gravitational wave background: developing statistical methods and analyzing data from ground-based detectors
• Untargeted Bayesian search of anisotropic gravitational-wave backgrounds through the analytical marginalization of the posterior
• Astrometry meets Pulsar Timing Arrays: Synergies for Gravitational Wave Detection
• Statistical effects of the observer's peculiar velocity on source number counts