No evidence for parity violation in BOSS

TL;DR

This paper critically examines claims of parity violation in the BOSS galaxy survey, introducing new statistical methods that show no significant evidence for such violation.

Contribution

The authors develop new statistics to separate parity violation signals from 8PCF biases, enabling unbiased tests in galaxy survey data.

Findings

No significant parity violation detected in BOSS data.

New statistics effectively distinguish parity signals from biases.

Results suggest previous claims of parity violation may be due to bias.

Abstract

Recent studies have found evidence for parity violation in the BOSS spectroscopic galaxy survey, with statistical significance as high as $7\sigma$. These analyses assess the significance of the parity-odd four-point correlation function (4PCF) with a statistic called $\chi^2$. This statistic is biased if the parity-even eight-point correlation function (8PCF) of the data differs from the mock catalogs. We construct new statistics $\chi^2_\times$, $\chi^2_{\mathrm{null}}$ that separate the parity violation signal from the 8PCF bias term, allowing them to be jointly constrained. Applying these statistics to BOSS, we find that the parity violation signal ranges from $0$ to $2.5\sigma$ depending on analysis choices, whereas the 8PCF bias term is $\sim 6\sigma$. We conclude that there is no compelling evidence for parity violation in BOSS. Our new statistics can be used to search for parity violation in future surveys, such as DESI, without 8PCF biases.