Recent content by Drew Carey

Thanks a lot for taking the time to reply. I would like to delay on each one of your paragraphs if you don't mind: By this do you mean the 3-velocity and 3-momentum? How do you settle the following equation...

Hi all, I'm having trouble with the concept of a co-moving frame, specifically in the context of constant proper-acceleration (hyperbolic motion). I feel like I don't "get it"; and perhaps this is related to some deeper misunderstandings I may have regarding the definitions of certain quantities...

Thanks! So basically it operates as it would on any function of space? What is the commutation relation between P and the field ladder operators?

I'm asking about the commutation relation between P and the field operator, not between P and X (which I realize now doesn't have an obvious 2nd Q parallel), but we can focus on the question in regards to P and the field operator.

Interesting, thanks, I haven't realized this; I'll look into this. However it does digress a bit from my question which I am willing to restrict to the momentum operator which definitely can be 2nd quantized...

Perhaps this isn't well defined? I can treat this by writing the 2nd quantized momentum or position operators in terms of the field ladder operators and then express my desired commutator as a pretty trivial commutator between ladder operators. Is this the only way to go about this? Doesn't...

Hi all, I haven't been able to find an answer online but this seems like a pretty basic question to me. What are the commutator relations between the position/momentum operators and the field operator? I'm not even certain what the commutation relations between X/P and a single ladder operator...

Can you please elaborate on the second part. What do you mean by " for scalar operators, the answer is clearly no."? If A and B commute with H then: [AB,H]=A[B,H]+[A,H]B=0 If the answer to my first question was #1, then for vector operators \vec A and \vec B that commute with H we would have...

Hi all, My motivation is understanding some derivations in Quantum Mechanics, but I think my questions are purely algebraic. I have a general question and then a specific one: General Question - when writing the commutator of commuting vector and a scalar operators (for instance angular...

Hi all! I was reading up on the Klein paradox in Itzykson & Zuber's Quantum Field Theory (but I think this is a pretty standard part that's probably present in most QFT textbooks) and on page 62 they have a pretty straight forward solution to the Dirac equation with a step potential. I've...