We propose a way of extending the Broad Histogram Monte Carlo method (BHMC)
to systems with continuous degrees of freedom, and we apply these ideas to
investigate the three-dimensional XY-model. Our method gives results in
excellent agreement with Metropolis and Histogram Monte Carlo simulations and
calculates for the whole temperature range 1.2<T<4.7 using only 2 times more
computer effort than the Histogram method for the range 2.1<T<2.2. Our way of
treatment is general, it can also be applied to other systems with continuous
degrees of freedom.Comment: LaTex, 5 pages, 2 eps figure