what is a virtual particle?

[Ruairi]

I have been doing a bit of reading into particle physics and quantum theory lately and I'm having a bit of trouble understanding what a virtual particle and how they are allowed if they break the law of conservation of energy.

[imatfaal]

There is not much that is forbidden for a virtual particle

 

Here is the good Doctor Matt Strassler

https://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

 

They are "off-shell" and do not have to obey many of the laws that real particles do.

 

https://en.wikipedia.org/wiki/On_shell_and_off_shell

 

Note that Noether's theorem is the mathematical treatment of conservation laws / invariance under transformation

[StringJunky]

From what I understand, from Mordred, is that it is a particle that, individually, has no action on other particles because its energy is too low; it needs to be a full quantum or more but they are actionable collectively.

[Mordred]

From what I understand, from Mordred, is that it is a particle that, individually, has no action on other particles because its energy is too low; it needs to be a full quantum or more but they are actionable collectively.

http://www.scienceforums.net/topic/106004-useful-fundamental-formulas-of-qft/#entry991940

 

Has the QFT breakdown though I hadn't gotten to describe how that post later applies to the Feymann diagrams under S matrix.

 

The VP being the internal lines, real particles the external lines on Feymann diagrams.

 

This Hobson paper relates though not specifically VP, but particles as field excitations.

 

https://arxiv.org/pdf/1204.4616.pdf

Edited June 30, 2017 by Mordred

[StringJunky]

http://www.scienceforums.net/topic/106004-useful-fundamental-formulas-of-qft/#entry991940

 

Has the QFT breakdown though I hadn't gotten to describe how that post later applies to the Feymann diagrams under S matrix.

 

The VP being the internal lines, real particles the external lines on Feymann diagrams.

 

This Hobson paper relates though not specifically VP, but particles as field excitations.

 

https://arxiv.org/pdf/1204.4616.pdf

But as a super-condensed neophyte description was it ok? If you had to write a one line description to a novice, how would you put it?

Edited June 30, 2017 by StringJunky

[Mordred]

Your shortened anecdote is fine, I would end up with a similar statement.

[StringJunky]

Your shortened anecdote is fine, I would end up with a similar statement.

Super. You are very good at posting on the appropriate level for a given type of audience.

Edited July 1, 2017 by StringJunky

[Mordred]

Thanks I appreciate the accolade