The Relaxion Measure Problem

Understand

We examine the necessity of requiring that relaxion dynamics is dominated by classical slow roll and not quantum fluctuations.

• It has been recently proposed by Nelson and Prescod-Weinstein that abandoning this requirement can lead to a unified solution of the hierarchy and strong CP problems in QCD relaxion models.
• In more general models this results in a higher value of the allowed cut-off.
• In this work we find, however, that relaxing this condition and can result in the universe being dominated in physical volume by regions arising from large quantum fluctuations of the relaxion.