Mohamad Shalaby

No cosmological constraints on dark photon dark matter from resonant conversion:
Impact of nonlinear plasma dynamics

Anson Hook, Junwu Huang, and Mohamad Shalaby arXiv:2510.13956; submitted as PRL

This work overturns all previous constraints on dark photon dark matter by showing that its resonant conversion into ordinary plasma is highly inefficient, saturating at a very low level. As a result, the limits on dark photon dark matter are weakened by a factor of 3,000 to 10 million, rendering it effectively undetectable by current and near-future cosmological observations.

In the animations below: wavemode \(k = 2\pi/\lambda\), with marked scales \(k_D = 1/\lambda_D\) and \(\omega_p = 1/\lambda_e\) where \(\lambda\) is the wavelength, \(\lambda_D\) is the Debye length, and \(\lambda_e\) is electron skin depth.