Dark Matter Microhalos in the Solar Neighborhood: Pulsar Timing Signatures of Early Matter Domination

Understand

Pulsar timing provides a sensitive probe of small-scale structure.

• Gravitational perturbations arising from an inhomogeneous environment could manifest as detectable perturbations in the pulsation phase.
• Consequently, pulsar timing arrays have been proposed as a probe of dark matter substructure on mass scales as small as $10^{-11} M_\odot$.
• Since the small-scale mass distribution is connected to early-Universe physics, pulsar timing can therefore constrain the thermal history prior to Big Bang nucleosynthesis (BBN), a period that remains largely unprobed.