  Recently it was proposed that asymptotically flat spacetimes have a
holographic dual which is an ultra-relativistic conformal field theory. In this
paper, we obtain the conformal anomaly for such a theory via the flat-space
holography technique. Furthermore, using flat-space holography we obtain a
C-function for this theory which is monotonically decreasing from the UV to the
IR by employing the null energy condition in the bulk.
