How Can Static Fields Be Effectively Handled in Quantum Field Theory?

[lalbatros]

Hello,

I just realized that I could not figure out how static fields can be handled in QFT.
Although I realize that really static fields don't really need QFT, I nevertheless would like to see how QFT covers this extreme case. Maybe a limit for low frequencies would be useful.

Have you any idea about that?
Thanks,

Michel

 

[Mr.Brown]

you mean by static field something like a static electric field pulling on charges.
That case is solved by exchange of virtual field quanta which can also posses negative momentum ( i think that´s where your problem lies doesn´t it :) ? )

For example 2 electrons moving towards each other exchange one quanta of positive momentum while they are repelled from each other.
Two protons instead exchange one quanta of negative momentum while attrackted to each other.

Hope i could help you :)