KOSTERLITZ-THOULESS PHASE-TRANSITIONS ON DISCRETIZED RANDOM SURFACES

The large N limit of a one-dimensional infinite chain of random matric es is investigated. It is found that in addition to the expected Koste rlitz-Thouless phase transition this model exhibits an infinite series of phase transitions at special values of the lattice spacing epsilon (pq) = sin(pi p/2q). An unusual property of these transitions is that they are totally invisible in the double scaling limit. A method which allows us to explore the transition regions analytically and to deter mine certain critical exponents is developed. It is conjectured that p hase transitions of this kind can be induced by the interaction of two -dimensional vortices with curvature defects of a fluctuating random l attice. (C) 1997 Elsevier Science B.V.