A Hamiltonian Perturbative Study of Lattice O(N) Model in the Broken PhaseThe project supported by Project 19705001 of National Natural Science Foundation of China (NNSFC), Climbing-Up Program and the Natural Science Fund from Peking University

The lattice O(N) model, defined on a large but finite three-dimensional cubic lattice, is studied using the Hamiltonian approach in bare perturbation theory in the broken phase. Renormalization is carried out to O(?0) and the results are compared with those obtained using the conventional Lagrangian approach in the infinite volume limit. Complete agreement is found between the two methods.