We discuss the implications of two possible , recent Sunyaev-Zel ’ dovich ( SZ ) detections for which no optical or X–ray counterparts have been found .
This suggests that the objects reside at high redshift , which is difficult to reconcile with a critical cosmology .
We develop this argument and find that an open model with \Omega _ { o } = 0.2 remains consistent with what we currently know about the two objects .
The reasoning also demonstrates the utility of SZ cluster searches .