  Discrete multiplicative turbulent cascades are described using a formalism
involving infinitely divisible random measures. This permits to consider the
continuous limit of a cascade developed on a continuum of scales, and to
provide the stochastic equations defining such processes, involving infinitely
divisible stochastic integrals. Causal evolution laws are also given. This
gives the first general stochastic equations which generate continuous
multifractal measures or processes.
