CONTRACTOR RENORMALIZATION-GROUP METHOD - A NEW COMPUTATIONAL TECHNIQUE FOR LATTICE SYSTEMS

The contractor renormalization group (CORE) method, a new approach to solving Hamiltonian lattice systems, is introduced. The method combine s contraction and variational techniques with the real-space renormali zation group approach. It applies to lattice systems of infinite exten t and is ideal for studying phase structure and critical phenomena. Th e CORE approximation is systematically improvable and can treat system s with dynamical fermions. The method is tested using the (1 + 1)-dime nsional Ising model.