Undergrad The virtual photon can turn into a virtual electron positron?

[Philipsmett]

for example, when does an electron repel another electron with an electromagnetic disturbance?

 

[PeterDonis]

when does an electron repel another electron with an electromagnetic disturbance?

I'm not sure what you mean. Can you narrow your question to a specific experimental scenario or a specific theoretical model?

 

[mfb]

for example, when does an electron repel another electron with an electromagnetic disturbance?

Same charges always repel.
How is this question related to the topic of this thread?

 

[Philipsmett]

I'm not sure what you mean. Can you narrow your question to a specific experimental scenario or a specific theoretical model?

when two electrons repel by virtual photon, can this photon transform into virtual electron positron pair?

 

[PeterDonis]

when two electrons repel by virtual photon, can this photon transform into virtual electron positron pair?

If you mean, can we observe this, no. We don't even observe virtual photons exchanged by electrons that are repelling each other; virtual photons are a property of a particular theoretical model. In that theoretical model, yes, some of the probability amplitude for electrons to repel each other is due to the creation (and destruction) of virtual electron-positron pairs from (and to) virtual photons. But this theoretical model has significant limitations and should not be taken too literally. We have an Insights article that discusses this:

https://www.physicsforums.com/insights/misconceptions-virtual-particles/

 

[Philipsmett]

If you mean, can we observe this, no. We don't even observe virtual photons exchanged by electrons that are repelling each other; virtual photons are a property of a particular theoretical model. In that theoretical model, yes, some of the probability amplitude for electrons to repel each other is due to the creation (and destruction) of virtual electron-positron pairs from (and to) virtual photons. But this theoretical model has significant limitations and should not be taken too literally. We have an Insights article that discusses this:

https://www.physicsforums.com/insights/misconceptions-virtual-particles/

Want to say that there is a possibility
that a virtual photon on its way turns into a virtual electron positron pair?
But as far as I understand, the more complex the process, the less likely it is to origin?

 

[PeterDonis]

Want to say that there is a possibility
that a virtual photon on its way turns into a virtual electron positron pair?

This describes a particular Feynman diagram that contributes to the calculated probability amplitude, yes. But, as I've already noted and as the Insights article goes into in some detail, this viewpoint has significant limitations and should not be taken too literally.

as far as I understand, the more complex the process, the less likely it is to origin?

The more vertexes there are in the Feynman diagram, the smaller its contribution to the calculated probability amplitude. (Note that this is true because the coupling constant for quantum electrodynamics is small; for an interaction like the strong nuclear force where the coupling constant is not small, the statement is not true, which makes it much, much harder to study such interactions using this method.)