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arXiv · 2609.09106

A Two-Dimensional Test of Cosmological Parity Violation with the 3-Point Correlation Function

William Ortolá Leonard·Zachary Slepian
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Abstract

Searches for parity violation (PV) in the Universe's large-scale structure have recently been carried out using parity-odd modes of the galaxy 4-Point Correlation Function (4PCF). Here, we introduce a new estimator for a 3-Point Correlation Function (3PCF) that is sensitive to PV. The construction exploits the handedness of triangles formed on 2D spherical shells, where mirror-image configurations cannot be related by proper rotations within the surface. By dotting the oriented area vector with an externally-defined normal vector to the shell, we obtain sensitivity to PV. We present a discrete estimator for this statistic and also show how to correct for the survey geometry. This parity-odd 3PCF provides a complementary test of PV in galaxy surveys and a potential cross-check of PV 4PCF measurements.

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William Ortolá Leonard, Zachary Slepian. 2026-09-08. A Two-Dimensional Test of Cosmological Parity Violation with the 3-Point Correlation Function. https://arxiv.org/abs/2609.09106

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