Detection and estimation of the cosmic dipole with the Einstein Telescope and Cosmic Explorer

Abstract

One of the open issues of the standard cosmological model is the value of the cosmic dipole measured from the Cosmic Microwave Background (CMB), as well as from the number count of quasars and radio sources. These measurements are currently in tension, with the number count dipole being 2-5 times larger than expected from CMB measurements. This discrepancy has been pointed out as a possible indication that the cosmological principle is not valid. In this paper, we explore the possibility of detecting and estimating the cosmic dipole with gravitational waves (GWs) from compact binary mergers detected by the future next-generation detectors Einstein Telescope and Cosmic Explorer. We model the expected signal and show that for binary black holes, the dipole amplitude in the number count of detections is independent of the characteristics of the population and provides a systematic-free tool to estimate the observer velocity. We introduce techniques to detect the cosmic dipole from number counting of GW detections and estimate its significance. We show that a GW dipole consistent with the amplitude of the dipole in radio galaxies would be detectable with $>3\sigma$ significance with a few years of observation ($10^6$ GW detections) and estimated with a $16\%$ precision, while a GW dipole consistent with the CMB one would require at least $10^7$ GW events for a confident detection. We also demonstrate that a total number $N_{\mathrm{tot}}$ of GW detections would be able to detect a dipole with amplitude $v_o/c\simeq 1/\sqrt{N_{\mathrm{tot}}}$.

10 pages, 10 figures. Updated to the published version. We also corrected a bug for Fig.1 and Fig.2 concerning the SNR calculation (missing 2.2 factor). Rest of the paper holds same conclusions

References in corpus (10)

• Cosmic Star Formation History
• Laser Interferometer Space Antenna
• Can environmental effects spoil precision gravitational-wave astrophysics?
• The Cosmic Linear Anisotropy Solving System (CLASS) I: Overview
• A Gravitational Wave Detector with Cosmological Reach
• The effect of matter structure on the gravitational waveform
• Cosmology and modified gravitational wave propagation from binary black hole population models
• On the kinematic cosmic dipole tension
• Euclid preparation: XIX. Impact of magnification on photometric galaxy clustering
• Doppler boosting the stochastic gravitational wave background

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• Aberration of gravitational waveforms by peculiar velocity
• Boosting gravitational waves: a review of kinematic effects on amplitude, polarization, frequency and energy density
• Combining chirp mass, luminosity distance and sky localisation from gravitational wave events to detect the cosmic dipole
• Dipole Anisotropy in Gravitational Wave Source Distribution
• The impact of large-scale galaxy clustering on the variance of the Hellings-Downs correlation: numerical results
• Statistical effects of the observer's peculiar velocity on source number counts
• Detector induced anisotropies on the angular distribution of gravitational wave sources and opportunities of constraining horizon scale anisotropies