2. Equations of motion respect relativity if the action is relativistically invariant. Sup pose t...
2. Equations of motion respect relativity if the action is relativistically invariant. Sup pose that the action can be written as S = JdtL and L = JofrC, where L is the Lagrangian density. In this exercise, you will verify that S is a Lorentz scalar if C is a Lorentz scalar. To do this, you want to verify that dd°dis ivari ant under Lorentz transformations. To do that, recall from your caleulus class how under changes of variables, the integration measure picks up a factor of the Jacobian determinant. Verify that the Jacobian determinant forA is equal to 1 for a boost along the x-axis and also for a rotation around the axis. Sow that AT'A = η implies that det A-: 1, and that transformations that are continuously connected to the identity must have det A-1 3. Using the fact that j"(cp, J) transforms as a 4-vector, and the result of the previous question, argue that electric Carge Q = Jd3zp is Lorentz invariant.
2. Equations of motion respect relativity if the action is relativistically invariant. Sup pose that the action can be written as S = JdtL and L = JofrC, where L is the Lagrangian density. In this exercise, you will verify that S is a Lorentz scalar if C is a Lorentz scalar. To do this, you want to verify that dd°dis ivari ant under Lorentz transformations. To do that, recall from your caleulus class how under changes of variables, the integration measure picks up a factor of the Jacobian determinant. Verify that the Jacobian determinant forA is equal to 1 for a boost along the x-axis and also for a rotation around the axis. Sow that AT'A = η implies that det A-: 1, and that transformations that are continuously connected to the identity must have det A-1 3. Using the fact that j"(cp, J) transforms as a 4-vector, and the result of the previous question, argue that electric Carge Q = Jd3zp is Lorentz invariant.