(Quasi)Localized Gauge Field on a Brane: Dissipating Cosmic Radiation to Extra Dimensions?

TL;DR

This paper introduces a mechanism for quasi-localizing massless gauge fields on a brane, allowing cosmic radiation to dissipate into extra dimensions at low frequencies, with potential astrophysical implications.

Contribution

It presents a new gauge field localization method that does not depend on BPS properties and enables cosmic radiation to dissipate into extra dimensions.

Findings

Gauge fields are effectively four-dimensional at short distances.

Cosmic radiation can dissipate into extra dimensions at low frequencies.

The mechanism may apply to lattice chiral fermion models.

Abstract

We propose a mechanism ensuring (quasi)localization of massless gauge fields on a brane. The mechanism does not rely on BPS properties of the brane and can be realized in any theory where charged particles are confined to the world-volume. The localized matter fluctuations induce a gauge kinetic term on the brane. At short distances the resulting propagator for the gauge field is {\it identical} to the four-dimensional propagator. The gauge theory on the brane is effectively four-dimensional at short distances; it becomes higher-dimensional on very large (cosmic) scales. The brane-bulk system exhibits the phenomenon of ``infrared transparency''. As a result, only very low frequency modes can escape into extra dimensions. In this framework the large wavelength cosmic radiation can dissipate in extra space at a rate that may be observable, in principle. We briefly discuss some astrophysical consequences of this scenario. The same mechanism of localization of gauge fields may work in Kaplan's framework for domain wall chiral fermions on lattices.