Particle States in Quantum Field Theory: Local vs. Global Approximations

[qsa]

I think that the notion of a particle is one of those concepts that's just too useful to give only definition. One needs to be flexible. It can be a little classical ball bouncing around or a quantum particle that sniffs out its surroundings or a little packet of energy or a representation of the asymptotic poincare group or the quanta of a field or any number of other variations on the theme. Even virtual particles can have a place. Each point of view has its own intuitive advantages and each points to different forms of generalization.

For example, the field point of view is quite useful. Unlike the concept of representation of the poincare group, the concept of a quantum field is easily generalized to situations without poincare symmetry or even without crisp particle-like excitations at all. In my opinion, it pays to understand as many of the points of view as one can, within reason.

It's like a tapestry (or manifold!) where you patch together a global understanding of the concept of a particle from lots of little pieces that each capture some of the intuition and meaning.

Obviously present day theories model “particles” that way. But the question was is that really satisfactory. It is bad enough to swallow the particle-wave duality, but the interaction picture and all of its associated concepts make one really wonder, even the working scientists themselves don’t feel easy about it.

What is needed is a theory that describes entities just like QM i.e. probabilities in space, and when interaction happens entities mesh and form new probabilities in space. And when they separate the separated probabilities look like the usual entities. How can that happen? I think we must explain how the typical entities form a stable structure. This is a very old question, started with Lorentz, and people are still working on it. It is called the ”electromagnetic mass”. Moreover, the particle sniffing the entire universe is real, that is how you should get the gravity. That is already been postulated by the holographic principle.


Both above concepts must be unified in one coherent theory. I know it is possible(very). Reality is very weird, but not QFT weird.

 

[Demystifier]

..is this generally accepted as "observational proof" of virtual particles?

Of course it isn't.