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Lagrangian formalism

  1. May 19, 2009 #1

    May anybody tell the pre-reqs (on calculus) for learn the lagrangian formalism used on quantum field theory ? :confused:

  2. jcsd
  3. May 19, 2009 #2


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    well integration and differentiation with several variables, functionals
  4. May 19, 2009 #3
    In addition, a knowledge of basic Newtonian mechanics is helpful.

    However, you mention its use in QFT. If that's your goal, you'll need a lot more physics. In the introduction to his QFT book, Mark Srdnecki gives a set of equations, mostly from QM, that one should be familiar with as prerequisites. See page 8 of


    Expressed in English, you should be comfortable with:

    1. Differential scattering cross-section.
    2. Creation and annihilation operators.
    3. Angular momentum ladder operators.
    4. Evolution of operators in the Heisenberg picture.
    5. Obtaining the Hamiltonian from the Lagrangian.
    6. Lorentz transformations.
    7. Relativistic energy-momentum.
    8. Electromagnetic vector potential.

    Topics that are covered in good QM, E&M, and mechanics texts.
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