A Non-perturbative Solution of the Zero-Dimensional lambda phi^4 Field Theory

A. P. C. Malbouisson, R. Portugal, N. F. Svaiter

We have done a study of the zero-dimensional $\lambda {\varphi }^4$ model. Firstly, we exhibit the partition function as a simple exact expression in terms of the Macdonald's function for $Re(λ)…