Classical field theory and classical mechanics

수학노트
http://bomber0.myid.net/ (토론)님의 2010년 3월 16일 (화) 09:32 판
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introduction
  • can be formulated using classical fields and lagrangian density
  • change the coordinates and fields accordingly
  • require the invariance of action integral over arbitrary region
  • this invariance consists of two parts : Euler-Lagrange equation and the equation of continuity

 

 

Euler-Lagrange equation
  • if field satisfies the equation of motion, EL is satisfied
    \(\partial_\mu \left( \frac{\partial \mathcal{L}}{\partial ( \partial_\mu \psi )} \right) - \frac{\partial \mathcal{L}}{\partial \psi} = 0.\)

 

 

equation of continuity
  • current density \(J_{\mu}=(J_0,J_1,J_2,J_3)\) satisfies
    \(\partial^{\mu} J_{\mu}=0\)
  • we get a conserved quantity
    \(G=\int_V J_0(x) \,d^3 x\)
  • Lagrangian can be used to express the current density explicity

 

 

 

currents
  • quantum analogues of the conser

 

 

history

 

 

related items

 

 

books

 

 

encyclopedia

 

 

question and answers(Math Overflow)

 

 

blogs

 

 

articles

 

 

 

experts on the field

 

 

TeX