On the type of the temperature phase transition in phi-4 model

The temperature induced phase transition is investigated in the one-component scalar field \phi^4 model on a lattice by using Monte Carlo simulations. Using the GPGPU technology a huge amount of data is collected that gives a possibility to determine the Linde-Weinberg low bound on the coupling constant \lambda_0 and investigate the type of the phase transition for a wide interval of coupling values. It is found that for the values of \lambda close to this bound a weak-first-order phase transition happens. It converts into a second order phase transition with the increase of \lambda. A comparison with analytic calculations in continuum field theory and lattice simulations obtained by other authors is given.