Abstract
A new variational wave function is proposed for the ground state of Bose liquids. It consists of a Jastrow function multiplied by exponentials of three-particle functions. The form of the wave function is deduced from a formal analysis carried out for the weakly interacting Bose gas characterized by a strength parameter λ. By using the wave function proposed here, the energy obtained is exact to O(λ4). Several useful and straightforward applications of the new method to liquid helium and Coulomb gases are suggested.