# Measuring dark matter-neutrino relative velocity on cosmological scales

## TL;DR

This paper proposes a novel cosmological method to measure neutrino masses by analyzing the dark matter-neutrino relative velocity through a parity-odd bispectrum, promising high significance detection with future surveys.

## Contribution

It introduces a new technique leveraging the parity-odd bispectrum from dark matter-neutrino relative velocity, unaffected by common systematics and optical depth uncertainties.

## Key findings

- Potential to detect minimal neutrino mass sum with upcoming surveys.
- The method is robust against many systematic errors.
- Provides a new avenue for neutrino mass measurement in cosmology.

## Abstract

We present a new method to measure neutrino masses using the dark matter-neutrino relative velocity. The relative motion between dark matter and neutrinos results in a parity-odd bispectrum which can be measured from cross-correlation of different cosmic fields. This new method is not affected by most systematics which are parity even and not limited by the knowledge of optical depth to the cosmic microwave background. We estimate the detectability of the relative velocity effect and find that the minimal sum of neutrino masses could be detected at high significance with upcoming surveys.