2019/11/30 by Roy Maartens, Sheean Jolicoeur, Obinna Umeh +4
Physics and Astronomy · #Astronomy #Astrophysics #Bispectrum #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Physics #Pulsars and Gravitational Waves Research #Quantum mechanics #Redshift #Redshift survey #Redshift-space distortions #Relativistic quantum chemistry #Spectral density #Statistics #astro-ph.CO
paper · pdf · doi:10.1088/1475-7516/2020/03/065
published as JCAP03(2020)065 · 13 pages, 10 figures, Typo in equation (3.8) corrected - results unchanged
openalex publication_date 2020/03/31 · arxiv created 2021/08/04 · arxiv updated 2021/08/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
The Fourier galaxy bispectrum is complex, with the imaginary part arising from leading-order relativistic corrections, due to Doppler, gravitational redshift and related line-of-sight effects in redshift space. The detection of the imaginary part of the bispectrum is potentially a smoking gun signal of relativistic contributions. We investigate whether next-generation spectroscopic surveys could make such a detection. For a Stage IV spectroscopic H α survey similar to Euclid, we find that the cumulative signal to noise of this relativistic signature is (10). Long-mode relativistic effects couple to short-mode Newtonian effects in the galaxy bispectrum, but not in the galaxy power spectrum. This is the basis for detectability of relativistic effects in the bispectrum of a single galaxy survey, whereas the power spectrum requires multiple galaxy surveys to detect the corresponding signal.