Chiral symmetry breaking in three-dimensional quantum electrodynamics as fixed point annihilation

Spontaneous chiral symmetry breaking in three-dimensional (d = 3) quantum electrodynamics is understood as annihilation of an infrared-stable fixed point that describes the large-N conformal phase by another unstable fixed point at a critical number of fermions N = N-c. We discuss the root of universality of N-c in this picture, together with some features of the phase boundary in the (d, N) plane. In particular, it is shown that as d -> 4, N-c -> 0 with a constant slope, our best estimate of which suggests that N-c = 2.89 in d = 3.