Recent content by johnahn

Lagrangian I have is little bit massy so I don't write in here. Like in ψψ(dagger) , or ψ∅ -> ψ∅, How can I calculate the differential cross section or total, or amplitudes?

The problem is showing (□+m^2)<0| T(∅(x)∅(y)) |0> = -δ^4 (x-y) I know that it is relavent to Green's function, but the problem is that it should be alternatively solved without any information of Green's function, and using equal time commutation relations. Does Anyone know that?

How can Eddington-Finkelstein coordinate be transformed into Lemaitre coordinate? I know the transformation between the Lemaitre and Schwarzschild coordinate, and also between Eddington-Finkelstein and Schwarzschild coordinate. So I tried to find the connection between Lemaitre and E-F...

Oh, I find such region... It was very simple. If we draw the asymtotic line of the hyperbola that is the uniformly accelerated observer, then that line will meet with the x-axis at a point. And the light emitted by the source behind that point, never reaches the observer forever because the...

Is there a region that the light never reaches the 'uniformly accelerated' observer? Of course, light travels in the same direction the observer moves. It sounds weird for me... I derive the parameterization of t and x, and gets hyperbola. So I try to find with drawing that in the ST...

I saw that the norm of four acceleration is equal to the magnitude of proper frame's acceleration. So, if the observer moves in x direction, following equation about norm of it's 4 acceleration is like that -(d^2 t / dτ^2) + (d^2 x / dτ^2) = d^2 x / dt^2 In comoving frame(proper frame)...