Suppression of scalar perturbations due to a heavy axion
Kai-Ge Zhang, Jian-Feng He, Chengjie Fu, Zong-Kuan Guo
公開日: 2025/10/3
Abstract
A fast-rolling axion can transfer its kinetic energy to gauge fields via the Chern-Simons coupling, leading to copious production of gauge quanta during inflation. The amplified gauge fields act as a source for both scalar and tensor perturbations. In this work, we propose a mechanism for suppressing scalar perturbations while sourcing strong tensor perturbations. We present an implementation of such a mechanism, demonstrating that sourced tensor perturbations are expected to be detected by upcoming next-generation CMB experiments.