Recent content by QuantumDevil

Such as?

How so? Can you explain it? I though that invariance with respect to Lorentz transformation imposed causality and locality

Maybe it comes from Gell-Mann–Nishijima phenomenological formula which relates SU(2) weak isospin I_z, weak hypercharge Y and electric charge Q? \qquad Q = I_z + {1 \over 2} Y

http://arxiv.org/abs/hep-th/0212049v3" Abstract: An elementary introduction to perturbative renormalization and renormalization group is presented. No prior knowledge of field theory is necessary because we do not refer to a particular physical theory. We are thus able to disentangle what...

At page 52 of 4th chapter in "An Introduction to gauge theories & modern particle physics" by Leader & Predazzi one can find such statement: "We must therefore rearrange (4.2.4) so that we can identify the field that multiplies\frac{1}{2}\left(1+\tau_{3}\right) as gauge boson that remains...

okey, you're right it's my mistake. His question was about mass term for gauge bosons not matter fields.

Page 346 below equation 58.7

Read chapers: 54, 58 and 69. of this book -> http://www.physics.ucsb.edu/~mark/ms-qft-DRAFT.pdf In chapters 58 and 69 it is explicitly stated that theory with mass term in Lagrangian don't forbid gauge invariance!

No, small coupling constant of EM field to fermions is the reason that cross section for such process is very small. Moreover photon-photon scattering is the process of 4th order.

Photon-Photon scattering is possible but this effect is observable in fields of extreme strength.

1. Are there possible (4th order)process of "decay of photon" \gamma\rightarrow 3 \gamma with one-photon initial state and 3-photon final state? Intuition tells me there are no such processes. But because of crossing symmetry of scattering amplitude one can argue that such processes should be...

http://homerreid.ath.cx/~homer/physics/peskin/index.shtml http://www-personal.umich.edu/~jbourj/qft.htm http://www.physics.rutgers.edu/%7Ermagyar/physics/index.html

I saw an interesting attempt to find PDE for photons made by Polish physicist Bialynicki-Birula: http://www.cft.edu.pl/~birula/publ/APPPwf.pdf http://www.cft.edu.pl/~birula/publ/reconstr.tex http://www.cft.edu.pl/~birula/publ/CQO7.pdf

I dont' actually understand the notion "full multiparticle interacting QFT in 4D" introduced by You and the difference between it and "full interacting Hamiltonian". (Maybe the reason is that I'm not native English speaker). Could you explain it in more detailed way or give me some references...

I don't know. Therefore I asked question in the first message.