Apparent parity violation in the observed galaxy trispectrum

Abstract

Recent measurements of the 4-point correlation function in large-scale galaxy surveys have found apparent evidence of parity violation in the distribution of galaxies. This cannot happen via dynamical gravitational effects in general relativity. If such a violation arose from physics in the early Universe it could indicate important new physics beyond the standard model, and would be at odds with most models of inflation. It is therefore now timely to consider the galaxy trispectrum in more detail. While the intrinsic 4-point correlation function, or equivalently the trispectrum, its Fourier counterpart, is parity invariant, the observed trispectrum must take redshift-space distortions into account. Although the standard Newtonian correction also respects parity invariance, we show that sub-leading relativistic corrections do not. We demonstrate that these can be significant at intermediate linear scales and are dominant over the Newtonian parity-invariant part around the equality scale and above. Therefore when observing the galaxy 4-point correlation function, we should expect to detect parity violation on large scales.

8 pages, 6 figures. v2 has minor errors corrected and additional material and figures. Version to appear in Physical Review Letters

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Cited by in corpus (6)

• Anatomy of Parity-violating Trispectra in Galaxy Surveys
• Doppler bias: impact of peculiar velocities on color selection and the large scale structure of galaxy surveys
• A Match Made in Heaven: Linking Observables in Inflationary Cosmology
• Signatures of asymmetry: Gravitational wave memory and the parity violation
• The Odd-Parity Part of the Observed Galaxy Trispectrum
• Visualising relativistic effects in redshift space distortions of large scale structure