On four-point correlation functions in simple polymer models

Abstract

We derive an exact formula for the covariance of Cartesian distances in two simple polymermodels: the freely jointed chain and a discrete flexible model with nearest-neighborinteraction. We show that even in the interaction-free case, correlations exist as long as thetwo distances at least partially share the same segments. For the interacting case, wedemonstrate that the naive expectation of increasing correlations with increasinginteraction strength only holds for a finite range of values. Some suggestions for futuresingle-molecule experiments are made.