We show how canonical ensemble expectation values can be extracted from
quantum Monte Carlo simulations in the grand canonical ensemble. In order to
obtain results for all particle sectors, a modest number of grand canonical
simulations must be performed, each at a different chemical potential. From the
canonical ensemble results, grand canonical expectation values can be extracted
as a continuous function of the chemical potential. Results are presented from
the application of this method to the two-dimensional Hubbard model.Comment: 5 pages, 5 figure