Title: Dynamics of Relaxed Inflation,
Abstract: The cosmological relaxation of the electroweak scale has been proposed as a
mechanism to address the hierarchy problem of the Standard Model. A field, the
relaxion, rolls down its potential and, in doing so, scans the squared mass
parameter of the Higgs, relaxing it to a parametrically small value. In this
work, we promote the relaxion to an inflaton. We couple it to Abelian gauge
bosons, thereby introducing the necessary dissipation mechanism which slows
down the field in the last stages. We describe a novel reheating mechanism,
which relies on the gauge-boson production leading to strong electromagnetic
fields, and proceeds via the vacuum production of electron-positron pairs
through the Schwinger effect. We refer to this mechanism as Schwinger
reheating. We discuss the cosmological dynamics of the model and the
phenomenological constraints from CMB and other experiments. We find that a
cutoff close to the Planck scale may be achieved. In its minimal form, the
model does not generate sufficient curvature perturbations and additional
ingredients, such as a curvaton field, are needed.