Title: Moyennes effectives de fonctions multiplicatives complexes,
Abstract: We establish effective mean-value estimates for a wide class of
multiplicative arithmetic functions, thereby providing (essentially optimal)
quantitative versions of Wirsing's classical estimates and extending those of
Halász. Several applications are derived, including: estimates for the
difference of mean-values of so-called pretentious functions, local laws for
the distribution of prime factors in an arbitrary set, and weighted
distribution of additive functions.