Emmy Noether’s Wonderful Theorem

http://www.springerlink.com/content/m500g70515681003/fulltext.pdf

[1]http://dx.doi.org/10.1063/PT.3.1263

 

48p

In constrast to Hamilton's principle, relativistic mechanics postulates that, of all world lines through spacetime that a freely falling particle might follow from even A to even ZB, the world line actually followed is the one for which the elapsed proper time is a maximum. Let us call this "Fermat's principle for relativistic partivles. It has been enormously successful, for example, in predicting gravitational redshfit, precession of orbit perihelion, deflection of starlight, gravitational lensing, and the relativistic precession of gyroscopes.

 

 

50p constrained Lagrangian http://farside.ph.utexas.edu/teaching/336k/newton/node90.html Lagrange multiplier method ?