Relaxion for the weak scale hierarchy

Recently cosmological relaxation of the Higgs boson mass has been proposed as an alternative solution to the weak scale hierarchy problem.  After a brief review of this new proposal, I discuss several issues on the relaxion scheme, including

the clockwork mechanism to generate the required hierarchy among the relaxion scales, a variety of observational constraints on the relaxion, and the possibility of high reheating temperature after the cosmological relaxation of the Higgs mass.