  Confinement is a versatile and well-established tool to study the properties
of polymers either to understand biological processes or to develop new
nano-biomaterials. We investigate the conformations of a semiflexible polymer
ring in weak spherical confinement imposed by an impenetrable shell. We develop
an analytic argument for the dominating polymer trajectory depending on polymer
flexibility considering elastic and entropic contributions. Monte Carlo
simulations are performed to assess polymer ring conformations in probability
densities and by the shape measures asphericity and nature of asphericity.
Comparison of the analytic argument with the mean asphericity and the mean
nature of asphericity confirm our reasoning to explain polymer ring
conformations in the stiff regime, where elastic response prevails.
