Abstract:
A scheme of resummation of singularities related to the Goldstone singularities is suggested for the series of $4-\varepsilon$ expansions of the Green functions of the $n$-component $\Phi^4$ theory below the critical temperature. Using this scheme it is proved (in the arbitrary order of the $\varepsilon$ expansion) that the scaling functions in the neighbourhood of the critical point have the same asymptotics at small external field and momenta as those predicted by the “hydrodynamic approximation”.