1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Hamiltonian math

  1. Dec 9, 2012 #1
    I'm watching a lecture on the Hamiltonian and can't figure out something. Here it is. Take a generic function G, and differentiate it with respect to p and q. What you get is the partial of G with respect to p TIMES the derivative of p (or p-dot), plus the derivative of G with respect to q TIMES q-dot.

    My question is, where does the p-dot and q-dot terms come into the equation here? Why isn't it just the partial of G over p plus the partial of G over q?
     
  2. jcsd
  3. Dec 9, 2012 #2

    jtbell

    User Avatar

    Staff: Mentor

    What you've described looks like taking the derivative of G(p,q) with respect to t, using the chain rule:

    $$\frac{dG(p,q)}{dt} = \frac{\partial G}{\partial p} \frac{dp}{dt} + \frac{\partial G}{\partial q} \frac{dq}{dt}$$
     
  4. Dec 9, 2012 #3
    It certainly does, thanks jtbell.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Hamiltonian math
  1. Hamiltonian Function (Replies: 16)

  2. The Hamiltonian (Replies: 7)

  3. Classical Hamiltonian (Replies: 4)

  4. Hamiltonian Density? (Replies: 1)

Loading...