Particle creation in (2+1) circular dust collapse

We investigate the quantum particle creation during the circularly symmetric collapse of a 2+1 dust cloud, for the cases when the cosmological constant is either zero or negative. We derive the Ford-Parker formula for the 2+1 case, which can be used to compute the radiated quantum flux in the geometric optics approximation. It is shown that no particles are created when the collapse ends in a naked singularity, unlike the 3+1 case. When the collapse ends in a BTZ black hole, we recover the expected Hawking radiation.