On the elimination of the t-explicit divergence in the calculation of transport coefficients

Through an analysis of the expression of the autocorrelation function of the velocities in the matrix representation, an identification is made of all the matrix elements which lead to the so-called t or ? explicit divergence. The terms in the expansion can be easily summed and as a result the divergence is eliminated. A comparison with the procedure recently developed by Bartis and Oppenheim is made.