Intensity interferometry for ultralight bosonic dark matter detection

Ultralight bosonic dark matter (UBDM) can be described by a classical wave-like field oscillating near the Compton frequency of bosons. If measurement scheme for direct detection UBDM interactions is sensitive to signature quadratic in field, then there near-zero-frequency (dc) component signal. Thus, detector with given finite bandwidth used search bosons frequencies many orders magnitude larger than its bandwidth. This opens possibility analogous Hanbury Brown and Twiss intensity interferometry. Assuming that virialized galactic gravitational potential, random velocities produce slight deviations from frequency. These result stochastic fluctuations on time scale determined spread kinetic energies. In order mitigate ubiquitous local low-frequency noise, network sensors measuring cross-correlation between sensors. method inherently broadband, since large range will yield components within sensor searched simultaneously. Measurements existing networks have sufficient sensitivity experimentally unexplored parameter space.