Crossover diagram for

It is of interest to trace out patlis in the w — / diagram corresponding to typical experiments. 

Accidentally this relation agrees with Eq. (9.33), defining the tricritical region. This coincidence happens only in three dimensions. Indeed, our crossover diagrams ignore the three-body forces which induce an additional structure in the 0-region. This structure involves the strength of the three-body interaction as a new scale and therefore is not fixed relative to the curves shown here. 

---