Thermal Misalignment of Scalar Dark Matter

Understand

The conventional misalignment mechanism for scalar dark matter depends on the initial field value, which governs the oscillation amplitude and present-day abundance.

• We present a mechanism by which a feeble (Planck-suppressed) coupling of dark matter to a fermion in thermal equilibrium drives the scalar towards its high-temperature potential minimum at large field values, dynamically generating misalignment before oscillations begin.
• Unlike conventional misalignment production, the dark matter abundance is dictated by microphysics and not by initial conditions.
• As an application of the generic mechanism, we discuss a realistic scenario in which dark matter couples to the muon.