CRITICAL-BEHAVIOR OF VORTICES IN A LAYERED SYSTEM

The critical behavior of vortices interacting in zero field in a syste m of weakly coupled layers is studied. A mathematically rigorous, real -space renormalization group study is carried out and the recursion re lations derived. A new term is found which corresponds to the effect o f vortex fluctuations on the interlayer coupling and which tends to de couple the layers just above the transition, a result which is consist ent with Monte Carlo studies. The effect of vortices in neighboring la yers on the critical behavior is also studied. We find that it reinfor ces slightly the upward shift of the transition temperature with the i nterlayer coupling, but is otherwise minimal over most of the temperat ure range.