Thompson's method applied to diffusion limited chemical reaction A+B -> 0,with different initial concentrations of the two species

In this work we use Thompson's renormalization group method to treat diffus ion limited chemical reactions A + B --> 0 (inert product), with unequal in itial concentrations of the two species, by considering rho (A)(0) much les s than rho (B)(0). For d less than or equal to 2, we obtain stretched expon ential decaying of the specie A, which is in agreement with rigorous result of Bramson and Lebowitz. For d > 2, we obtain simple exponential decaying of the specie A.