Work

Cosmological-perturbation equations from the total-angular-momentum formalism

Year: 2026

Type: preprint

Abstract: We derive the equations for the linear evolution of cosmological perturbations using total-angular-momentum (TAM) waves. The cosmic microwave background temperature and polarization transfer functions are first derived as integral equations and from these the usual Boltzmann hierarchy of differential equations are then obtained for both scalar and tensor perturbations. We include the effects of isotropic cosmic birefringence and discuss anisotropic cosmic birefringence. We note a subtle effect of cosmic birefringence on temperature fluctuations. The TAM derivation of the equations provides physical insights to results obtained previously.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2609.36000

Authors: Kamionkowski, Marc, Caldwell, Robert R.

Institutions: Johns Hopkins University, Dartmouth College

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, National Aeronautics and Space Administration, John Templeton Foundation

Awards: G2433409076, Theoretical Physics From Quantum Fields to the Cosmos, Gravitational waves for cosmology, gravity, and quantum mechanics

OpenAlex ID: W7214951704

Cites: 54

Cited by: 2

Related to: 10