Measurement of Parity-Violating Modes of the Dark Energy Spectroscopic Instrument (DESI) Year 1 Luminous Red Galaxies' 4-Point Correlation Function

Zachary Slepian; Alex Krolewski; Alessandro Greco; Simon May; William Ortola Leonard; Farshad Kamalinejad; Jessica Chellino; Matthew Reinhard; Elena Fernandez; Francisco Prada; Steven Ahlen; Davide Bianchi; David Brooks; Todd Claybaugh; Axel de la Macorra; Arnaud de Mattia; Biprateep Dey; Peter Doel; Enrique Gaztanaga; Gaston Gutierrez; Klaus Honscheid; Dragan Huterer; Dick Joyce; Robert Kehoe; David Kirkby; Theodore Kisner; Martin Landriau; Laurent Le Guillou; Marc Manera; Aaron Meisner; Ramon Miquel; Seshadri Nadathur; Will Percival; Ashley Ross; Eusebio Sanchez; David Schlegel; Michael Schubnell; Hee-Jong Seo; Joseph Silber; David Sprayberry; Gregory Tarle

arXiv · 2508.09133

Measurement of Parity-Violating Modes of the Dark Energy Spectroscopic Instrument (DESI) Year 1 Luminous Red Galaxies' 4-Point Correlation Function

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Abstract

Here we report the first measurement of the parity-violating (PV) 4-Point Correlation Function (4PCF) of the Dark Energy Spectroscopic Instrument's Year 1 Luminous Red Galaxy (DESI Y1 LRG) sample, motivated by the potential detection of the PV 4PCF in the Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey (SDSS BOSS) galaxies. In our auto-correlation ("auto") analysis, we find a statistically significant excess of the PV signal compared to mocks without any PV, at 4-10$σ$ depending on details of the analysis. This could arise either from genuine PV or from an underestimation of the variance in the mocks; it is unlikely to arise, at the signal level, from a systematic. We then cross-correlate ("cross") the putative PV signal between different, independent patches of sky, and there find no detection of parity violation. The two measurements are in significant tension: while the cross has somewhat larger error bars than the auto, this is not sufficient to explain the discrepancy. We thus present the current work as an intriguing addition to the PV work on BOSS and as motivation for exploring further the relationship between the auto and cross PV 4PCF analyses.

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Zachary Slepian, Alex Krolewski, Alessandro Greco, Simon May, William Ortola Leonard, Farshad Kamalinejad, Jessica Chellino, Matthew Reinhard, Elena Fernandez, Francisco Prada, Steven Ahlen, Davide Bianchi, David Brooks, Todd Claybaugh, Axel de la Macorra, Arnaud de Mattia, Biprateep Dey, Peter Doel, Enrique Gaztanaga, Gaston Gutierrez, Klaus Honscheid, Dragan Huterer, Dick Joyce, Robert Kehoe, David Kirkby, Theodore Kisner, Martin Landriau, Laurent Le Guillou, Marc Manera, Aaron Meisner, Ramon Miquel, Seshadri Nadathur, Will Percival, Ashley Ross, Eusebio Sanchez, David Schlegel, Michael Schubnell, Hee-Jong Seo, Joseph Silber, David Sprayberry, Gregory Tarle. 2025-08-12. Measurement of Parity-Violating Modes of the Dark Energy Spectroscopic Instrument (DESI) Year 1 Luminous Red Galaxies' 4-Point Correlation Function. https://arxiv.org/abs/2508.09133

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