  The search for dark matter is of fundamental importance to our understanding
of the universe. Weakly-Interacting Slim Particles (WISPs) such as axions and
hidden sector photons (HSPs) are well motivated candidates for the dark matter.
Some of the most sensitive and mature experiments to detect WISPs rely on
microwave cavities, and the detection of weak photon signals. It is often
suggested to power combine multiple cavities, which creates a host of technical
concerns. We outline a scheme based on cross-correlation for effectively power
combining cavities and increasing the signal-to-noise ratio of a candidate WISP
signal.
