Lensing signals from Spin-2 perturbations

TL;DR

This paper calculates the lensing signals caused by spin-2 perturbations, including gravitational waves and tensor perturbations, providing new insights into their effects on CMB power spectra and anisotropic spacetimes.

Contribution

It introduces a formalism to compute lensing signals from spin-2 perturbations, extending analysis to Bianchi I spacetimes with anisotropy.

Findings

Derived angular power spectra for E-type and B-type lensing potentials.

Computed tensor-lensed CMB power spectra for inflationary gravitational waves.

Applied formalism to anisotropic Bianchi I spacetime.

Abstract

We compute the angular power spectra of the E-type and B-type lensing potentials for gravitational waves from inflation and for tensor perturbations induced by scalar perturbations. We derive the tensor-lensed CMB power spectra for both cases. We also apply our formalism to determine the linear lensing potential for a Bianchi I spacetime with small anisotropy.