Cosmic microwave background polarization, Faraday rotation and stochastic gravity-waves backgrounds

TL;DR

This paper explores how primordial magnetic fields could cause Faraday rotation of the CMB polarization, linking it to stochastic gravitational wave backgrounds and implications for superstring cosmology.

Contribution

It proposes a mechanism for generating large-scale magnetic fields from vacuum fluctuations influenced by dilaton evolution, connecting polarization rotation with gravitational waves in superstring models.

Findings

Magnetic fields from vacuum fluctuations can rotate CMB polarization.

Faraday rotation signals are connected to stochastic gravity-wave backgrounds.

Implications for superstring inspired cosmological models.

Abstract

A magnetic field, coherent over the horizon size at the decoupling and strong enough to rotate the polarization plane of the CMBR, can be generated from the electromagnetic vacuum fluctuations amplified by the space-time evolution of the dilaton coupling. The possible relevance of this result for superstring inspired cosmological models is discussed. Particular attention will be paid to the connection between Faraday rotation signals and stochastic gravity-wave backgrounds.