Recent content by kdv

Are you 100% sure they are asking a graph of -dE/dP vs E?? I would be willing to bet that this is a typo and they really are just asking a plot of -dE/dx vs E, which is then simple, they just want the graph of the expression they provided. (By the way, their definition of reduced mass is very...

Ah ok, so the P's are permutations. I see that you assume that S=1. This is no stated in the question, so I think you will have to double check with your instructor because the question is ambiguous. S could be 0 (making the problem trivial) or 2, etc. The degeneracy will depend on that (unless...

Thank you. Yes, this is helpful. I had looked at many of these but could not find a source that included all the uncertainties summarized and given for a specific model, so I was hoping someone would know of a specific source that would provide this. But I guess I will have to follow your...

It's not quite right. You have to consider the effect of ##\psi## and its adjoint on both a fermion and an anti-fermion state (so essentially, you need four calculations). The fermion state is ##|p,r \rangle = a_r^\dagger(p,r) |0\rangle ## whereas the antifermion state is ##|p,r \rangle =...

I am not sure what your S and A stand for here. You wrote the correct spatial wavefunction. I am not sure what your ket ## |33 \rangle ## stand for either. You said that they are bosons, but their spin is not specified? If not, then, how many different spin states can you have in the ground...

Thank you. I had googled several of these scenarios but never found any references that specifically address the questions I raised in my first post. So if anyone know of a specific reference covering these questions, I would be grateful.

I have seen that many posters here seem to be very knowledgeable about the man made climate "emergency". So someone can surely point out a reference where all the sources of uncertainties for at least one specific model are provided with an estimate of their values (for examples, uncertainties...

Since it is real, its complex conjugate is just psi(x). x-x0 remains x-xo (assuming that they are real, which they surely are meant to be).

It is easier to differentiate with respect to time \int dx |\psi(x,t)^2 and then use Schrödinger's equation for the derivatives of \psi and \psi^*.

This is indeed correct and is the only way to do it. If it seems very convoluted, it is just that it is new. The only way to shorten it is to work directly with the difference of the phases at X (which is all that matters), but that really does not change all your reasoning.

I have my questions. To get the vector multiplet, we must take H' to be [1/2]. Indeed, $$ [\frac{1}{2}] \otimes \biggl( [\frac{1}{2}] + 2 [0] \biggr) = [1] + [0] + 2 [\frac{1}{2}] $$ which is the particle content of a vector supermultiplet. It's that simple.

I am trying to reproduce a very simple result that involved evaluating the refined index for a vector supermultiplet but ran into a snag. I hope someone will be able to clear that up easily. Apparently for a half vector multiplet (meaning that we do not include the CPT conjugated states), the...

Exactly. Just do a Taylor expansion, for example ## b(t_2 + \Delta t_2) \approx b(t_2) + \Delta t_2 \frac{db}{dt}(t_2) ## The second term is simply ## \Delta t_2 ~ \frac{1}{a(t_2)} ##.

In the information loss paradox, people say that in quantum mechanics , time evolution is unitary. They usually do not say anything about the measurement process of if they do, they briefly say that the measurement process does not violate unitarity either if one takes into account the...

But what does that mean exactly? There is no way to make a sphere rotate in such a way that it will have that moment of inertia, so it is actually a completely unphysical result. That's why it is never quoted as a moment of inertia of a sphere.