We study the complex |\psi |4 theory in three dimensions and compare our numerical results with a recently proposed mean-field like approximation. The mean-field result, which predicts a first-order phase transition in parts of the phase diagram, cannot be confirmed. To get a closer look inside this discrepancy, we introduce a generalized Hamiltonian with an additional fugacity term. With this modification we can show that the complex |\psi |4 theory can indeed be tuned to undergo a first-order phase transition by varying the strength of the new term in the generalized Hamiltonian.
PACS numbers: 02.70.Lq, 64.60.--i, 74.20.De
| Table of Contents | Back to Number 10 contents |