Phase transition in light-front (1+1)-dimensional φ4 theory -: art. no. 085008

We reproduce Chang's duality condition in a regularized (1+1)-dimensional phi(4) theory quantized on the light front. The regularization involves higher derivatives in the Lagrangian, renders the model finite in the ultraviolet, and does not require the introduction of a finite size of the system. It is demonstrated that light-front quantization is a natural way to treat systems with higher derivatives. The phase transition is related to the presence of tachyons in the regularized theory. The prospects for computing the critical coupling in this formulation are briefly discussed.