Kinks in Discrete Light Cone Quantization

TL;DR

This paper explores topological structures like kinks in Discrete Light Cone Quantization of 2D $f extphi^4$ theory, revealing degenerate ground states and calculating kink properties through variational and DLCQ methods.

Contribution

It provides the first detailed analysis of kink solutions and topological features in DLCQ of 2D $f extphi^4$ theory, combining numerical and variational approaches.

Findings

Evidence of degenerate ground states indicating spontaneous symmetry breaking

Extraction of vacuum energy and kink mass consistent with classical results

Comparison of boson density and form factor with variational kink state

Abstract

We investigate non-trivial topological structures in Discrete Light Cone Quantization (DLCQ) through the example of the broken symmetry phase of the two dimensional $\phi^4$ theory using anti periodic boundary condition (APBC). We present evidence for degenerate ground states which is both a signature of spontaneous symmetry breaking and mandatory for the existence of kinks. Guided by a constrained variational calculation with a coherent state ansatz, we then extract the vacuum energy and kink mass and compare with classical and semi - classical results. We compare the DLCQ results for the number density of bosons in the kink state and the Fourier transform of the form factor of the kink with corresponding observables in the coherent variational kink state.