Recent content by lzydesmond

You need to define the axis for the spin and determine the axis for the boost as well. After that, you just need to do some calculations for the amplitude and square it for the probability.

okay I kind of understood what you have said. You used the boost matrix (which is also the spin matrix) \vec{s}\cdot\vec{\sigma} by taking its eigenvalue, (s here) to show the above equation for spin rotation operator. But the equivalent for boost operator would be without the i right? The state...

Hi, I have tried to search for a general boost operator but to no avail. I understand that exp(-i(\vartheta/2)(n\cdot\sigma)) is the spin operator around axis n, where n is a unit vector. May I ask what is the equivalent for boost operator? Also, I don't see how exp(is) changes the magnitude of...

Okay, I think I kind of get what you mean. Because exp(-i(alpha/2) has modulus 1, the magnitude remains unchanged. Could you clarify on this part (as quoted above)? What are boost operations?

Thank you for your reply ok so in short, whenever a spin rotation matrix is used (around any axis), angle alpha measured in the orientation of the flag changes so the flag rotates and the flag has a period of 720 degrees (which corresponds to 2 full circles). This term exp(-i(alpha/2) boosts...

yes I kind of get what you mean by a spinor represents a rotation. Actually I would think it is a spin state, a state whereby we can express in terms of eigenspinors. I mean I found their conceptualization quite useful, except for the flag rotation part. Is there a better conceptualization? or...

okay thanks for your reply. The part on the global phase and the phase introduced by spin rotations is still not resolved though. I am still unsure whether the flag actually rotates during a rotation.

hi there, it seems that no one has an answer/understood what I was saying. I gave some though to the issue... what I think is that the rotation of the flag (angle alpha) has no effect on rotations. it is what is called global phase factor I believe? exp(-i(alpha)/2) I think I got muddled up...

Hi all, I am troubled by the flag and flagpole analogy for two-spinors and would like some clarification. Please refer to the post by Hans de Vries. https://www.physicsforums.com/showthread.php?t=239191 Am I right to say that the usage of spin rotation operators (eg...