Three-Particle Variational Wave Function for Bose Liquids

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 $\lambda$. By using the wave function proposed here, the energy obtained is exact to $O\left({\lambda }^4\right)$. Several useful and straightforward applications of the new method to liquid helium and Coulomb gases are suggested.