Recent content by Arnd Obert

  1. Arnd Obert

    Undergrad Density of states with delta function

    This is great, thank you very much! You are completely right with your assumption about the many particle system. Now the last part remains: When evaluating the geometric series, I get a density of states which looks like $$\Omega(\epsilon)=\frac{1}{2\pi}\int dk\exp\left(N\left[ik\epsilon-\ln...
  2. Arnd Obert

    Undergrad Density of states with delta function

    The End of #3 is the correct result but I have to find the way to get there. Thank you! I will try the tensor products.
  3. Arnd Obert

    Undergrad Density of states with delta function

    When multiplying $$e^{ikE1} \cdot e^{-ikH}$$ you get $$e^{ikE} e^{-ikH}$$ because ##e^{ikE1}## is diagonal, isn't it? And then you can pull it out of the trace? Thank you a lot, but now it got even worse: This Hamiltonian should be inserted $$H = \sum_{j=1}^{N}\hbar\omega(a_j^{\dagger}a_j +...
  4. Arnd Obert

    Undergrad Density of states with delta function

    Hello, I'm stuck with this exercise, so I hope anyone can help me. It is to prove, that the density of states of an unknown, quantum mechanical Hamiltonian ##\mathcal{H}##, which is defined by $$\Omega(E)=\mathrm{Tr}\left[\delta(E1\!\!1-\boldsymbol{H})\right]$$ is also representable as...
  5. Arnd Obert

    What is NMR Geophysics and How Does it Impact the Field of Physics?

    Hey you all, I'm new here and looking forward to having a good time in this forum. My name is Arnd, studying physics in the 10th semester and working on my master thesis in NMR geophysics right now. Cheers