Neutrino Fields in a Sandwich Gravitational Wave Background

TL;DR

This paper solves the linearized Einstein-Weyl equations exactly in a sandwich gravitational wave background, revealing how neutrino energy-momentum redistributes and varies, which could inform cosmological neutrino studies.

Contribution

It provides an exact solution for neutrino fields in a sandwich gravitational wave background, a novel analysis in this context.

Findings

Neutrino energy-momentum redistributes depending on wave geometry

Neutrino energy density varies between positive and negative extrema

Potential implications for understanding weakly interacting neutrinos in cosmology

Abstract

Sandwich gravitational waves are given globally in terms of step functions at the boundaries. Linearized Einstein-Weyl equations are solved exactly in this background in Rosen coordinates. Depending on the geometry and composition of the sandwich wave, the neutrino's energy-momentum redistributes itself. At the test field level, since the background will not change, the neutrino's energy density in particular will show variations between positive and negative extrema when crossing the sandwich wave. This may reveal facts about the weakly interacting neutrinos in cosmology.