What does the capital W stand for?

[Mikko Artsola]

<Edited by moderator.>

What does the capital W in this formula from this video stand for? work?

 

[Mikko Artsola]

http://www.symmetrymagazine.org/article/the-deconstructed-standard-model-equation

"The Lagrangian is a fancy way of writing an equation to determine the state of a changing system and explain the maximum possible energy the system can maintain ... Despite appearances, the Lagrangian is one of the easiest and most compact ways of presenting the theory."