CRITICAL (Phi^{4}_{3,\epsilon}) Auteur(s): Brydges D. C., Mitter P., Scoppola B. (Article) Publié: Communications In Mathematical Physics, vol. 240 p.281-327 (2003) Texte intégral en Openaccess : Ref HAL: hal-00176682_v1 Ref Arxiv: hep-th/0206040 DOI: 10.1007/s00220-003-0895-4 WoS: 000185597800012 Ref. & Cit.: NASA ADS Exporter : BibTex | endNote 37 Citations Résumé: The Euclidean $(\phi^{4})_{3,\epsilon$ model in $R^3$ corresponds to a perturbation by a $\phi^4$ interaction of a Gaussian measure on scalar fields with a covariance depending on a real parameter $\epsilon$ in the range $0\le \epsilon \le 1$. For $\epsilon =1$ one recovers the covariance of a massless scalar field in $R^3$. For $\epsilon =0$ $\phi^{4}$ is a marginal interaction. For $0\le \epsilon < 1$ the covariance continues to be Osterwalder-Schrader and pointwise positive. After introducing cutoffs we prove that for $\epsilon > 0$, sufficiently small, there exists a non-gaussian fixed point (with one unstable direction) of the Renormalization Group iterations. These iterations converge to the fixed point on its stable (critical) manifold which is constructed. Commentaires: 49 pages, plain tex, macros included |