Axial gravitational waves in FLRW cosmology and memory effects

Abstract

We show initial data for gravitational axial waves, that are twice differentiable but which are not $C^2$. They generate wave pulses that interact with matter in the radiation cosmological era. This forces the radiation matter to rotate. This rotation is permanent - it persists after the passage of the gravitational pulse. The observed inhomogeneities of the cosmic microwave background radiation put a bound onto discontinuities of superhorizon metric perturbations. We explicitly show that a class of smooth initial metrics that are at least $C^2$ gives rise to gravitational wave pulses that do not interact with the background during the radiation epoch.

This version matches the published article (Phys. Rev. D 96, 063523 (2017)). A note is added on interaction of axial gravitational waves with stars' interiors, with 3 new references

References in corpus (2)

• Chiral Primordial Gravitational Waves from a Lifshitz Point
• Axial and polar gravitational wave equations in a de Sitter expanding universe by Laplace transform

Cited by in corpus (2)

• Propagation of Polar Gravitational Waves in f(R,T) Scenario
• Propagation of Axial and Polar Gravitational Waves in Kantowski-Sachs Universe