Comment on "Critical behavior of a two-species reaction-diffusion problem".
In a recent paper, de Freitas et al. [Phys. Rev. E 61, 6330 (2000)] presented simulational results for the critical exponents of the two-species reaction-diffusion system A+B-->2B and B-->A in dimension d=1. In particular, the correlation length exponent was found as nu=2.21(5) in contradiction to the well-known relation nu=2/d. In this Comment, the symmetry arguments leading to exact critical exponents for the universality class to which this reaction-diffusion system belongs are concisely reconsidered.
Janssen
H K
HK