Fresh look at randomly branched polymers
Institut für Theoretische Physik III, Heinrich-Heine-Universität - 40225 Düsseldorf, Germany, EU
2 Department of Physics and Astronomy, University of Pennsylvania - Philadelphia, PA 19104, USA
Accepted: 14 May 2010
We develop a new, dynamical field theory of isotropic randomly branched polymers, and we use this model in conjunction with the renormalization group (RG) to study several prominent problems in the physics of these polymers. Our model provides an alternative vantage point to understand the swollen phase via dimensional reduction. We reveal a hidden Becchi-Rouet-Stora (BRS) symmetry of the model that describes the collapse (θ-)transition to compact polymer conformations, and calculate the critical exponents to 2-loop order. It turns out that the long-standing 1-loop results for these exponents are not entirely correct. A runaway of the RG flow indicates that the so-called θ'-transition could be a fluctuation-induced first-order transition.
PACS: 64.60.ae – Renormalization-group theory / 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion / 64.60.Ht – Dynamic critical phenomena
© EPLA, 2010