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Magnetic potential

  1. Feb 13, 2009 #1
    Until about ten minutes ago I had never heard of the magnetic vector potential [tex] \vec A [/tex], defined such that

    [tex] \vec B = \nabla \times \vec A [/tex].

    I am having trouble visualizing this. What would the magnetic vector potential field look like around a straight wire carrying a (constant) electric current?
  2. jcsd
  3. Feb 13, 2009 #2


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  4. Feb 13, 2009 #3
    Thanks atyy, that's a great reference.
  5. Feb 14, 2009 #4
    Follow up:

    Is the Lagrangian of a charged particle in an electromagnetic field

    [tex] L = \frac {1}{2}m( \dot x ^2 + \dot y^2 + \dot z^2 ) - q \phi + q (\dot x A_x + \dot y A_y + \dot z A_z) ? [/tex]

    (I'm not sure if that should be [tex] -q \phi [/tex] or [tex] + q \phi [/tex].) If so, is this good for both static and changing EM fields?

    Edit: oh wait, here it is. Equation 1.34. at


    All set, then.
    Last edited: Feb 14, 2009
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