Recent content by DannyJ108

  1. D

    ROC Curve: Background Rejection vs. Signal Efficiency

    Hello forum, I am reading this article on quantum machine learning. At one point in the article (page 7) they plot the ROC curve as background rejection vs. signal efficiency. Researching these concepts (since I did not understand them fully), I read that ROC curves should be plotted as TPR...
  2. D

    Cauchy's law from Lorentz model

    But I'm not approximating ##\sqrt{a + b}## I'm approximating: ##\sqrt{1 + a + b}##
  3. D

    Cauchy's law from Lorentz model

    I have rearranged the equation to get: ##n^2(\omega)=1+\frac {\frac {\omega_p^2} {\omega_0^2}} {1-\frac {\omega^2} {\omega_0^2}}## Since ##\omega << \omega_0##, ##\frac {\omega^2} {\omega_0^2}## will be smaller than 1, so I can expand that fraction as a Taylor series to get...
  4. D

    Cauchy's law from Lorentz model

    Yes, I do, but I don't know how I would get that expression with the equation I have. If ##\omega << \omega_0## , the equation would result in: ##n^2(\omega) = 1 + \frac {\omega^2_p} {\omega^2_0}##
  5. D

    Cauchy's law from Lorentz model

    Hello fellow physicists, I need to prove that when ##\omega << \omega_0##, Lorentz equation for refractive indexes: ##n^2(\omega) = 1 + \frac {\omega^2_p} {\omega^2_0 - \omega^2}## turns into Cauchy's empirical law: ##n(\lambda)=A+\frac B {\lambda^2}## I also need to express A and B as a...
  6. D

    Refractive index less than one

    Hello fellow users, I've been given the Lorentz model to calculate the refraction index of a dielectric, the formula in its simplest way states that: ##n^2(\omega) = 1 + \frac {\omega^2_p} {\omega^2_0 - \omega^2}## Where ##\omega_p## is the plasma frequency and ##\omega_0## is the resonance...
  7. D

    Help with neutron scattering in solid state physics

    Kinda hard finding it online and I doubt I'll buy it since I'll only make use of it once. Though I'm sure it's a great book, since I've seen it referenced in many places, do you know of any other good books on the subject?
  8. D

    Help with neutron scattering in solid state physics

    Do you think it's possible to do 10-15 pages talking about that only?
  9. D

    Help with neutron scattering in solid state physics

    Sorry to bring this thread back from the dead, but does neutron radiography count as neutron scattering? Also is neutron imaging and neutron tomography the same thing? If it is, is it also the same as neutron scattering or in the contrary case, what's the difference between them? I', so confused...
  10. D

    Rotational partition function for CO2 molecule

    Hello fellow physicists, I need to calculate the rotational partition function for a CO2 molecule. I'm running into problems because I've found examples were they say this rotational partition function is: ##\zeta^r= \frac T {\sigma \theta_r} = \frac {2IkT} {\sigma \hbar^3}## Where...
  11. D

    Help with neutron scattering in solid state physics

    Thank you for the answers, they were very helpful!
  12. D

    Help with neutron scattering in solid state physics

    Hello fellow physicists, I have a homework assignment which is to make a scientific essay (10-15 pages long) on neutron scattering in solid state physics. Our teacher is kind of the worse and he hasn't specified what he wants it on. He just said what I'm telling you: "An essay on neutron...
  13. D

    Equations of motion of a system with non holonomic constraints

    The homework statement specifically says that the constants are non holonomic, so approaching them as holonomic would be wrong I think. Also, I didn't mention it, but it says that ##A_1, A_2, B, C## and ##D## are constants independent of the generalized coordinates. I'm not sure if it makes a...
  14. D

    Equations of motion of a system with non holonomic constraints

    Hello, I have a system with 2 degrees of freedom with 2 non-holonomic constrains that can be expressed by:##A_1 dq_1 +Cdq_3 + Ddq_4 = 0## ##A_2 dq_1 + Bdq_2 = 0##Being ##q_1, q_2, q_3## and ##q_4## four generalized coordinates that can describe the movement of the system. And ##A_1, A_2, B...
Back
Top