Recent content by looseleaf

Thanks that makes sense. I was wondering if anyone could address another question I had? This one is from the Sidney Coleman lectures (2.72) ##e^{i P . x}\alpha(p)e^{-i P . x} = e^{-i p . x}\alpha(p)## i'm confused why we drop the operator on the right side when we go from 3-momentum to...

Hi, could someone please explain where the tau and sigma terms come from in this expression: I see the kinetic energy and quadratic "mattress" potential terms, but the tau and sigma kinda come out of nowhere. Where are they from?

Oh wait, I realize now it comes from the covariant transformation rules. Is it because we have to boost both the coordinate and the derivative operator?

Please help me understand this line from P&S, or point me towards some resources: Why is there another Lorentz transformation acting on the derivative on the RHS? Thanks

Thanks! So do you mean that the limits of integration are ##(-\infty , \infty)## which could just as well be ##(\infty, -\infty) ##?

Ok, I did those two integrals, then factor out the ##\omega_p## and foil out the c/a operators to get $$ \frac{1}{2}(a_p a_p^\dagger + a_{-p}a_{-p}^{\dagger}) $$ I see how this is equivalent to the final expression if -p = p, but how do you deal with those negative momenta? Can you just flip...

I was wondering how to deal with this step in Peskin and Schroeder: So first you make the delta fn. from the exponential as d(p - (- p')), then what do you do with the creation/annihilation operators that have a negative subscript? I don't have to go into position/momentum representation do I?..

Hello, I'm just starting Zee's QFT in a Nutshell, I'm a bit confused about what he means by "integate by parts under the d4x". Can someone explain what he means by this? I understand how to obtain the Klein-Gordon equation from the free particle Lagrangian density, but not sure why he invokes...

Thank you :)

Hi everyone, sorry for the basic question. But I was just wondering how one does the explicit coordinate change from dxdy to dr in the polar-coordinates method for solving the gaussian. I can appreciate that using the polar element and integrating from 0 to inf covers the same area, but how do...

Ok, I have been doing a little research and have realized that a key term I was missing was 'Informational Isolation'. So I guess what I am really asking about is the informational isolation between the nucleus of an atom and the external electrons. The electric and magnetic forces are pretty...

Ayy, that's my bad. Sorry, I will ask a mentor next time. Thank you for merging them!

Hi everybody! I asked this question a few days back over in High-Energy/Nuclear/Particle Physics, and I got some good answers, but I think this is probably a better place for it. So my question arose in the thinking about the dynamics of entanglement and decoherence in the context of nuclear...

Yes I admit I am talking about what is happening when we are not measuring the system. But I thought it was kind of an interesting question to think about the dynamics of entanglement even when we are not looking. Do you think my intuition is correct that the strong force would prevent the...

What type of interaction would that most likely be? A magnetic interaction with the nuclear spins and some external particle seems most likely to me. I can appreciate that there is no way to leverage such coherence, I was just wondering if it exists in theory. I can see how the incoming...