GROUND-STATE OF RANDOM COPOLYMERS AND THE DISCRETE RANDOM ENERGY-MODEL

We propose and investigate a modification of the random energy model w here the energies of different states are still independent random val ues but may take only discrete values. This model appears naturally in studies of random heteropolymers with monomers of two types. We calcu late the probability that the ground state of such a polymer is nondeg enerate and test this result against a lattice model of a heteropolyme r with exhaustively enumerated conformations. The theory is in excelle nt agreement with numerical experiment. Our results imply that the low er the energy of the ground state the less probable that it is degener ate. The probability of degeneracy decays exponentially as ground stat e energy decreases.