Tagged Questions
0
votes
1answer
74 views
Derivation of Dirac equation using the Lagrangian density for Dirac field
How can I find Dirac equation using the Lagrangian density for Dirac field?
2
votes
0answers
173 views
Prove that the first order perturbation theory overestimates fundamental state [closed]
This was a question on my exam and I don't know how to solve it.
Use the variational principle to prove that the first order perturbation theory always overestimates the energy of the fundamental ...
1
vote
1answer
153 views
Questions regarding solving the Brachistochrone problem using Lagrangian
brachistochrone problem: Suppose that there is a rollercoaster. There is point 1 ($0,0$) and point 2 ($x_2, y_2)$. Point 1 is at the higher place when compared to the point 2, so the rollercoaster ...
