title: High-order time expansion path integral ground state.
abstract: The feasibility of path integral Monte Carlo ground state calculations with very few beads using a high-order short-time Green's function expansion is discussed. An explicit expression of the evolution operator which provides dramatic enhancements in the quality of ground-state wave functions is examined. The efficiency of the method makes possible to remove the trial wave function and thus obtain completely model-independent results still with a very small number of beads. If a single iteration of the method is used to improve a given model wave function, the result is invariably a shadow-type wave function, whose precise content is provided by the high-order algorithm employed.
authors.affiliation: Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Rota
authors.forename: J
authors.initials: J
authors.lastname: Casulleras
authors.forename: F
authors.initials: F
authors.lastname: Mazzanti
authors.forename: J
authors.initials: J
authors.lastname: Boronat