Entropic Tightening
Even without interactions, knots could be `tight:'
Slip-links as surrogate (prime) knots:
Entropy of a constrained slip-link (phantom chain in three dimensions):
The most probable configurations are composed of a tight and an open loop!
Self-avoiding Slip-links:
A large body of work on polymer networks can be used to study slip-linked polymers.
The number of configurations of a self-avoiding slip-link has the scaling form
In the limit of a small (tight) loop, the above expression reduces to