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Homework Help: Canonical Transformation and harmonic-oscillator

  1. Dec 10, 2009 #1
    Show that the transformation
    Q = p + iaq , P = (p-iaq)/2ia
    is canonical and find the generating function. Use the transformation to solve the harmonic-oscillator problem.

    I was able to determine if the transformation is canonical, and it is. However, when it came to finding the generating function, I wasnt getting it right. And how do we use this transformation to solve the harmonic oscillator?
     
  2. jcsd
  3. Dec 11, 2009 #2

    gabbagabbahey

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    Well, what do you know about generating functions?...What does the Hamiltonian become under this transformation?
     
  4. Dec 11, 2009 #3
    I dont know how to obtain the Hamiltonian. But i know that to check whether the transformation is canonical, we can show that the Poisson brackets are invariant. Which I have shown they are. I'm not getting the right generating function, or is the generating function really the hamiltonian??
     
  5. Dec 11, 2009 #4

    gabbagabbahey

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    Well, what are you doing to obtain the (incorrect) generating function?

    You don't know what the Hamiltonian of the one-dimensional harmonic oscillator is?
     
  6. Dec 11, 2009 #5
    Ok so I take the poisson bracket and obtain 1, therefore its canonical. I have an example similar to this, so i take q = - partial F / partial p , so i solve from the original equation of Q = p + iaq, i solve for q and then take the integral and solve for F.
     
  7. Dec 11, 2009 #6
    Would the hamiltonian of a harmonic oscillator be H = p2/2 +(1/2)kx2
     
  8. Dec 11, 2009 #7
    sorry i meanH = p2/2m +(1/2)kx2
     
  9. Dec 11, 2009 #8
    H = p2/2m +(1/2)kq2
     
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