BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Alessandro Giuliani (Roma Tre) DTSTART:20220324T160000Z DTEND:20220324T173000Z DTSTAMP:20260423T035907Z UID:AQFP/17 DESCRIPTION:Title: Re normalization at all orders for lattice infrared QED4 with massless electr on\nby Alessandro Giuliani (Roma Tre) as part of Analysis\, Quantum Fi elds\, and Probability\n\n\nAbstract\nOne of the goals of constructive Qua ntum Field Theory (QFT) is to provide a convergent algorithm for computing a consistent set of Euclidean correlation functions starting from a given bare action and\, next\, to reconstruct the corresponding real-time corre lations via analytic continuation in the time variable. This program prove d successful for constructing several low dimensional toy QFT models but r esults in 3 and 4 dimensions are still scarce. Until now\, not even a cons istent construction of infrared QED4 with small electron mass at all order s in renormalized perturbation theory was available\, unless a loop regula rization scheme was employed or a number of non-gauge-invariant counter-te rms were included in the bare action.\nIn this talk I will describe such a consistent construction\, at all orders in renormalized perturbation theo ry\, in a lattice gauge theory model of QED4 with massless electron and no other counter-term than the one for the electron mass. We also prove that \, in the presence of an infrared (IR) cutoff on the photon propagator\, t he model is non-perturbatively well-defined\, provided the electron charge is sufficiently small (a priori\, non-uniformly in the IR cutoff).\nThe p roof is based on a Wilsonian Renormalization Group (RG) scheme and uses id eas developed in the last decade in the context of lattice gauge theory mo dels of graphene and Weyl semimetals. In particular\, we use Ward Identiti es at each RG step to control the flow of the effective couplings\, includ ing the non-gauge-invariant ones produced at intermediate steps by the mul tiscale procedure\, and prove their infrared asymptotic freedom. Time perm itting\, I will comment on the perspectives opened by this and related wor ks on the full construction of infrared QED4\, on the non-perturbative com putation of the chiral anomaly and on the spontaneous emergence of Lorentz symmetry. Joint work with Marco Falconi and Vieri Mastropietro.\n LOCATION:https://researchseminars.org/talk/AQFP/17/ END:VEVENT END:VCALENDAR