Is the K-G Operator of the Kelin-Gordon Equation a Time Ordered Function?

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Discussion Overview

The discussion revolves around the Klein-Gordon equation, particularly in the context of whether the Klein-Gordon operator can be considered a time-ordered function. Participants explore the implications of treating the wave function as an operator and the relationship between the Green function and the Klein-Gordon equation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions if the Klein-Gordon operator can be expressed as a time-ordered product of the wave function, suggesting a relationship between the scalar and operator forms of the wave function.
  • Another participant points out that the original equation presented lacks a Laplacian, indicating a potential misunderstanding of the Klein-Gordon equation.
  • A later reply clarifies that the wave function in the field equation is a classical field rather than a wave function, emphasizing the distinction between classical and operator treatments.
  • One participant references Schwinger's work on the Dirac equation and its Green function, expressing uncertainty about the derivation process.
  • Another participant requests references to Schwinger's paper to support the discussion on the Green function and functional derivatives.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the wave function in the context of the Klein-Gordon equation and the Green function. There is no consensus on whether the Klein-Gordon operator can be treated as a time-ordered function, and the discussion remains unresolved.

Contextual Notes

Participants note limitations in the original equation's formulation and the need for clarity regarding the definitions of terms used, such as "wave function" and "operator." There are unresolved mathematical steps and assumptions regarding the treatment of the Klein-Gordon equation.

Karlisbad
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Let be the Kelin-gordon equation (m=0) with a potential so:

[tex](-\frac{\partial ^{2}}{\partial t^{2}}+V(x) )\Phi=0[/tex]

my question is if you consider the wave function above as an operator..is the K-G operator of the form:

[tex]<0|T(\Phi(x)\Phi(x')|0>[/tex] T=time ordered

I think that in both cases..we use the same wave function but once is an scalar (or an spinor for electrons) and the other is an escalar...:shy: :shy:
 
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1.I don't know who Kelin was. Maybe you could supply some reference.

2. Your equation, misses a laplacian.

3. You depicted the Feynman Green function, which is a Green function for the operator written with a Laplacian.

All of course, if you mean "Klein-Gordon"

Daniel.
 
I apologize "DSextercioby"...:rolleyes: i missed the keyboard..:redface: yes i was referring Klein-Gordon equation with rest mass m=0 so:

[tex](-\frac{\partial ^{2}}{\partial t^{2}}+\nabla +V(x))\Phi=0[/tex]


then if you define the Green function by [tex]G(x,x')=<0|T(\Phi(x)\Phi(x'))0>[/tex]

then my question were if the "Phi" wave function defined in both G and K-G equation is the same ,but in one case is an operator and in the other is an scalar with T=time ordered product.

- By the way i looked at the paper by Scwinger ..taking the Dirac equation with Electromagnetism:

[tex](i\gamma_{\mu}\partial _{\mu}-eA_{\mu}+m)\Psi =0[/tex]

he got the Green function (i don't know how he did it.. ), he got the functional equation:

[tex] \partial _{\mu}-eA_{\mu}+m+\frac{\delta}{\delta J_{\mu}}G(x,x')=\delta(x-x')[/tex]
 
I figure you never read (hence never edit) your posts after hitting "submit reply/thread" button. :-p

In the field eqn, the [itex]\varphi (x)[/itex] is not a wavefunction, it is a classical field.

In the VEV of the time-ordered product, it is an operator acting on a Fock space. It still keeps the scalar behavior wrt restricted Poincare' transformations.

As for the second part of your post, please supply the reference to Schwinger's paper.

Daniel.
 
A brief resume..can be found at:

http://www.pnas.org/cgi/content/full/102/22/7783

with the Dirac equation + magnetic field+ scalar potential V(x) and the functional approach to the Green function involving functional derivatives.
 

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