On the approximation of the modified error function

摘要

In a recent research, the authors established an approximation to the modified error function (MEF) phi(delta) for a small positive thermal conductivity coefficient delta>0, leaving the problem open for the general case -1 0(+). In this paper, a new approximation to the MEF is found for -1 0(+/-). A comparative analysis shows that our proposed approximation gives a better estimate than the one in this recent reasearch by Ceratani et al.