Chetaev principle

A variational-differential principle of mechanics, a modification of the Gauss principle, established by N.G. Chetaev [1].

According to Chetaev's principle, the work on an elementary cycle, consisting of a direct motion in a fixed force field and an inverse (backward) motion in the force field, that would be sufficient for the creation of a real motion if the mechanical system were completely free, takes a relative (or global) maximum for the real motion in the class of all possible Gaussian motions. Chetaev's principle extends to physical systems and also to continuous media (cf. [2]).

For some more details cf. Variational principles of classical mechanics.

References

[1]	N.G. Chetaev, "Modification of the Gauss principle" Prikl. Mat. i Mekh. , 5 : 1 (1941) pp. 11–12 (In Russian)
[2]	V.V. Rumyantsev, "On the Chetaev principle" Dokl. Akad. Nauk SSSR , 210 : 4 (1973) pp. 787–790 (In Russian)