Strong-coupling expansion in the large-Nlimit

Abstract

We study a strong-coupling expansion of a ${\ensuremath{\phi}}^{4}$ quantum field theory with an $\mathrm{O}(N)$ internal symmetry. For large values of $N$ we observe that there is a critical point in $2lDl4$ dimensions and recover the known results for the two-point and the four-point Green's functions near the critical point, and for the critical exponent.