  We present a cosmological solution to the electroweak hierarchy problem.
After discussing general features of cosmological approaches to naturalness, we
extend the Standard Model with two light scalars very weakly coupled to the
Higgs and present the mechanism, which we recently introduced in a companion
paper to explain jointly the electroweak hierarchy and the strong-CP problem.
In this work we show that this solution can be decoupled from the strong-CP
problem and discuss its possible implementations and phenomenology. The
mechanism works with any standard inflationary sector, it does not require
weak-scale inflation or a large number of e-folds, and does not introduce
ambiguities related to eternal inflation. The cutoff of the theory can be as
large as the Planck scale, both for the Cosmological Constant and for the Higgs
sector. Reproducing the observed dark matter relic density fixes the couplings
of the two new scalars to the Standard Model, offering a target to future axion
or fifth force searches. Depending on the specific interaction of the scalars
with the Standard Model, the mechanism either yields rich phenomenology at
colliders or provides a novel joint solution to the strong-CP problem. We
highlight what predictions are common to most realizations of cosmological
selection of the weak scale and will allow to test this general framework in
the near future.
