COLLAPSE FROM LINEAR TO BRANCHED POLYMER BEHAVIOR

The asymptotic properties of a model of interacting linear polymer are studied exactly on Sierpinski gaskets. The model displays a new multicritical point corresponding to a collapse from linear into branched polymer, which is followed by a further transition into compact globule. Clear evidence of the first collapse is also obtained for a 2-tolerant trail model on the square lattice, previously introduced for the description of the THETA-transition.