Recent questions tagged action

We will have to shut down our server temporarily for maintenance. The downtime will start at Wednesday, 27. January 2021 at 12:00 GMT and have a duration of about two hours. Please save your edits before this time. Thanks for your patience and your understanding.

The action is the integral of the Lagrangian over time, or the integral of the Lagrangian Density over both time and space. I.e.

$$S=\int L\mbox{ d}t=\iiiint\mathcal L\mbox{ d}x^4$$

This is very useful in the Lagrangian reformulation of Classical Mechanics, where one may apply the least action principle to obtain the equations of motion.

Also useful in Quantum Mechanics, Quantum Field Theory, General Relativity, String Theory, and so on, due to the Path Integral and Variational formulations.

+ 1 like - 0 dislike
+ 1 like - 0 dislike
+ 5 like - 0 dislike
+ 1 like - 0 dislike
+ 3 like - 0 dislike
+ 7 like - 0 dislike
+ 7 like - 0 dislike
+ 4 like - 0 dislike
+ 3 like - 0 dislike
+ 4 like - 0 dislike
+ 3 like - 0 dislike
+ 2 like - 0 dislike
+ 6 like - 0 dislike