7. Chains and pseudocircles

Problem 7.1.
[R. Montgomery] What do pseudocircles really mean? More precisely:
(a) Is there a variational formulation of chains and pseudocircles? For example, is there a Finsler structure on $M^3$ which yields chains or pseudocircles as geodesics?
(b) Is there a Feffermantype construction that yields pseudocircles?
Cite this as: AimPL: Analysis and geometry on pseudohermitian manifolds, available at http://aimpl.org/pshermitian.