Footprints of Axion-Like Particle in Pulsar Timing Array Data and James Webb Space Telescope Observations

TL;DR

This paper explores how axion-like particles could leave detectable footprints in pulsar timing array data and JWST observations, linking early universe inhomogeneities to galaxy formation and future experimental searches.

Contribution

It proposes a novel connection between ALP domain walls, the stochastic gravitational-wave background, and high-redshift galaxy observations, offering new testable predictions.

Findings

ALP domain walls can produce a stochastic gravitational-wave background.

Predicted ALP photon coupling is within future experimental reach.

The model explains high-redshift observations by JWST.

Abstract

Several Pulsar Timing Array (PTA) collaborations have recently reported the evidence for a stochastic gravitational-wave background (SGWB), which can unveil the formation of primordial seeds of inhomogeneities in the early universe. With the SGWB parameters inferred from PTAs data, we can make a prediction of the seeds for early galaxy formation from the domain walls in the axion-like particles (ALPs) field distribution. This also naturally provides a solution to the observation of high redshifts by the James Webb Space Telescope. The predicted photon coupling of the ALP is within the reach of future experimental searches.