Asian Journal of Mathematics
We analyze the geometry of sub-Finsler Engel manifolds, computing a complete set of local invariants for a large class of these manifolds. We derive geodesic equations for regular geodesics and show that in the symmetric case, the rigid curves are local minimizers. We end by illustrating our results with an example.
Clelland, Jeanne N.; Moseley, Christopher G.; and Wilkens, George R., "Geometry of sub-Finsler Engel manifolds" (2007). University Faculty Publications. 465.