Left-invariant optimal control problems on Lie groups

Left-invariant optimal control problems on Lie groups form an important class of problems with big symmetry group. They are interesting from the theoretical point of view since they often can be completely studied, and general features can be investigated on these model problems. In particular, problems on nilpotent Lie groups give a fundamental nilpotent approximation of general problems. Left-invariant problems also often arise in applications: in classical and quantum mechanics, geometry, robotics, models of vision and image processing. This work aims to review the main notions, methods and results for left-invariant optimal control problems on Lie groups. The main attention is paid to description of extremal trajectories and their optimality, cut time and cut locus, optimal synthesis. Bibliography: 238 titles.