Totally singular Lagrangians and affine Hamiltonians.

A Lagrangian or an affine Hamiltonian is called totally singular if it is defined by affine functions in highest velocities or momenta respectively. A natural duality relation between these Lagrangians and affine Hamiltonians is considered. The energy of a second order affine Hamiltonian is related with a dual corresponding Lagrangian of order one. Relations between the curves that are solutions of Euler and Hamilton equations of dual objects are also studied using semi-sprays. In order to generate examples of second order, a natural lifting procedure is considered. [ABSTRACT FROM AUTHOR]