Recent content by doktorglas

I would argue that the whole point of the tensor index notation ##g_{\mu\nu}## is exactly the fact that we can write tensor equations without choosing any specific basis -- we only need the index structure of the constituent tensors. So, the symbol ##g_{\mu\nu}## is more of a placeholder for the...

Great reply, thank you! I was actually thinking something like an equals sign with a dot above, so I might have seen this somewhere. Just out of curiosity: Could you point to any references where some of these various alternatives are used? Particularly the...

Hi, I'm simply searching for some standard symbol (in place of an equals sign) to indicate that a matrix is a representative of a tensor in some given basis. Is there any standardized symbol like this, or how is this usually written in literature? E.g. say we have a O(1,1) metric tensor gμν...

Hi, I want to calculate the amount of liquid nitrogen (at boiling temp.) needed to build a pressure of 10.1 bar in a vessel of volume 66 m3. The liquid will be poured slowly into the vessel, boil off and fill the volume with gas at the specified pressure. I make the assumption that the process...

1. The scenario If we have a small cuboid volume embedded in a larger dito with periodic boundary conditions, and a wave function that is constant inside the former, while zero everywhere else; what can we then know about the momentum? Homework Equations I. Âψ = Aψ (A being the measured...

Well, it turns out that I partly misformulated myself again, and was somewhat right from the beginning. I will try to make sense now, and put it in a little more context. What I want to be zero is the following expression: -i\hbar∫dΩ(\overline{ψ_{1}}∇ψ_{2}+(∇\overline{ψ_{1}})ψ_{2}) =...

Thanks for the answers, but I'm sorry, I made an error in the formulation of the question. What I really meant was with the gradient inside of the integral, that is <p psi1 | psi2> in Dirac's notation. What I need is the gradient of (psi1-conjugate times psi2) to be zero for a proof I was...

Hi, Short question: If you take the inner product of two arbitrary wave functions, and then the gradient of that, the result should be zero, right? (Since the product is just a complex number.) Am I missing something? ∇∫dΩψ_{1}*ψ_{2} = 0

Indeed, that's what I did. But it doesn't take me anywhere: What I get is \overline{sinz} = \overline{\frac{cosz+isinz-cos(-z)-isin(-z)}{2i}} . And I don't see how I could turn that into the form \overline{z} = x-iy . Let alone...

The problem is to show sin\overline{z} = \overline{sinz}. What I need is help to get going.We know that sinz = \frac{e^{iz}-e^{-iz}}{2i}I can't see the first step in this. What I've tried to do is expressing sin\overline{z} and \overline{sinz} in terms of the above equation, but I don't know...