content_image/333110.jpg
<img src='content_image/333110.jpg'>

Extending the code from two dimensions to three dimensions is trivial and the chance for mistakes is rather small. However, we have tested the code at least at µ = 0 using the results from previous work. Here we compare results for χ obtained using the worm algorithm with that obtained using the microcanonical improved Metropolis (MM) algorithm and the available results in the literature using the cluster method [28]. The comparison is shown in Table VII. The reason for us to choose β = 0 . 45421 is because this is known to be the critical value of the coupling where the theory undergoes a phase transition from a normal phase to a superfluid phase. At the critical coupling we expect χ ∝ L $^{γ/ν}$. A fit of our data to this form yields the value of γ/ν = 1 . 99 as expected from [28], and is shown in figure 10. 

