NONPERTURBATIVE DYNAMICS FOR ABSTRACT (P,Q) STRING NETWORKS - ART. NO. 084033

We describe abstract (p, q) string networks which are the string netwo rks of Sen without the information about their embedding in a backgrou nd spacetime; The non-perturbative dynamical formulation invented for spin networks, in terms of causal evolution of dual triangulations, is applied on them. The formal transition amplitudes are sums over discr ete causal histories that evolve (p,q) string networks. The dynamics d epend on two free SL(2, Z) invariant functions which describe the ampl itudes for the local evolution moves. [S0556-2821(98)05020-6].