Relevance of the scheme of regularization of the density-of-state fluctuation contribution in an arbitrary magnetic field

The problem of the regularization of the fluctuations induced renormalizati on of the one-electron density of states (DOS) has been recently clarified. So far, only the weak-field limit was considered because of the field depe ndence of the cutoff in the DOS expression. Recently, theoretical results [ A. I Buzdin and A. A. Varlamov, Phys. Rev. B 58, 14 195 (1998)] have propos ed a scheme of regularization of the problem allowing numerical calculation s for an arbitrary magnetic field. By comparing magnetoconductivity measure ments under a strong magnetic field and the theoretical predictions, the ro bustness of the expression for the DOS contribution obtained as a convergen t series independent of cutoff is shown. Such an analysis allows us to calc ulate the zero-field contribution of the fluctuations to the measured resis tivity. The great influence of this effect on both the magnitude and the te mperature dependence of the resistivity above T-c is demonstrated.