Gaussian, Mean Field and Variational Approximation: the Equivalence
Emil V. Prodan · arXiv (Cornell University) · 1999
We show the equivalence between the three approximation schemes for self-interacting (1+1)-D scalar field theories. Based on rigorous results of [1, 2], we are able to prove that the Gaussian approximation is very precise for certain limits of coupling constants. The $λϕ^{4}+σϕ^{2}$ model will be used as a concrete application.