2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/112102The low-energy theory of interacting electrons on graphene's two-dimensional honeycomb lattice is derived and discussed. In particular, the Hubbard model in the large-N limit is shown to have a semi-metal - antiferromagnetic insulator quantum critical point in the universality class of the Gross-Neveu model. The same equivalence is conjectured to hold in the physical case N=2, and its consequences for various physical quantities are examined. The effects of the long-range Coulomb interaction and of the magnetic field are discussed.four pages, one figure; few typos corrected, references addedMesoscale and Nanoscale PhysicsStrongly Correlated ElectronsHigh Energy Physics - Theorytext