In [[General Relativity]], the Least Action Principle states that the motion of a particle on a [[surface]] M must be a [[geodesic]] of M, so it must minimize the geodesic functional. Additionally, the [[Einstein]] field equations follow from applying the principle of least action to the action functional <math>\int R_{g}d\mathrm{vol}_g</math>, where the minimization takes place over the space of [[metric]]s <math>g</math> on spacetime, and <math>R_g</math> denotes the scalar [[curvature]] of the metric. | In [[General Relativity]], the Least Action Principle states that the motion of a particle on a [[surface]] M must be a [[geodesic]] of M, so it must minimize the geodesic functional. Additionally, the [[Einstein]] field equations follow from applying the principle of least action to the action functional <math>\int R_{g}d\mathrm{vol}_g</math>, where the minimization takes place over the space of [[metric]]s <math>g</math> on spacetime, and <math>R_g</math> denotes the scalar [[curvature]] of the metric. |