Sunday 24 June 2018

lagrangian formalism - Energy-momentum tensor of the Dirac field


I'm trying to compute the energy momentum tensor for the dirac field $$\mathcal{L}=\bar\psi(i\gamma_\mu\partial^\mu-m)\psi $$$$T^{\mu\nu}=\frac{\partial\mathcal{L}}{\partial(\partial_\mu\psi)}\partial^\nu\psi-\eta^{\mu\nu}\mathcal{L}$$ and I'm not clear on how to treat the term in $\eta^{\mu\nu}\mathcal{L}$: the first term gives $i\bar\psi\gamma^\mu\partial^\nu\psi$ which is the tensor given by Peskin-Schroeder but I don't get how to compute the term in $\eta$




No comments:

Post a Comment

Understanding Stagnation point in pitot fluid

What is stagnation point in fluid mechanics. At the open end of the pitot tube the velocity of the fluid becomes zero.But that should result...