Search Results
| Search type | Search syntax |
|---|---|
| Tags | [tag] |
| Exact | "words here" |
| Author |
user:1234 user:me (yours) |
| Score |
score:3 (3+) score:0 (none) |
| Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
| Views | views:250 |
| Code | code:"if (foo != bar)" |
| Sections |
title:apples body:"apples oranges" |
| URL | url:"*.example.com" |
| Saves | in:saves |
| Status |
closed:yes duplicate:no migrated:no wiki:no |
| Types |
is:question is:answer |
| Exclude |
-[tag] -apples |
| For more details on advanced search visit our help page | |
Results tagged with quantum-field-theory
Search options not deleted
user 7924
Quantum Field Theory (QFT) is the theoretical framework describing the quantisation of classical fields which allows a Lorentz-invariant formulation of quantum mechanics. QFT is used both in high energy physics as well as condensed matter physics and closely related to statistical field theory. Use this tag for many-body quantum-mechanical problems and the theory of particle physics. Don’t combine with the [quantum-mechanics] tag.
6
votes
Interacting representation of the Poincaré group
There is no rigorous proof for this, as there is no known way to make sense of the interaction part of a local Hamiltonian at fixed time in such a way that $H$ becomes self-adjoint. The reason is that …
- 45.7k
1
vote
Accepted
Current formula and form factor
Your term is allowed, and in fact present in QED. It gives the anomalous magnetic form factor contribution to the current. In QED, The number $2F(0)$ is the anomalous magnetic moment of the electron. …
- 45.7k
1
vote
Questions concerning some parts of the section on one-particle states in Weinberg's first vo...
''Choosing'' the momentum states orthonormal works because momentum states are joint eigenstates of the (commuting, Hermitian) components of momentum, not because one can make arbitrary choices.
For …
- 45.7k
2
votes
Where can one learn about dispersion relations for S-matrices?
Bjorken & Drell's QFT book. It is old but therefore strong on this point.
- 45.7k
1
vote
Quantum State of Photon Question
Photons always have spin 1, this means that they have two transversal polarization indices - not spin indices, just as in the classical case.
In the helicity formalism, the two indices describe left …
- 45.7k
1
vote
In, QFT, do the excitations in the quantum fields exist physically?
Properties of the quantum fields (its mass density, charge density, response to external fields, etc.) can be measured and predicted in the same way as all quantum observables. There is therefore noth …
- 45.7k
4
votes
Accepted
Coherent state of charged field
There is an extensive survey paper by Zhang, Feng, and Gilmore that discusses coherent states for many different systems, both from a theoretical and a practical point of view. In particular, their un …
- 45.7k
1
vote
What is the exact definition of 'consistent field theory'?
The paper referenced, http://www.sciencedirect.com/science/article/pii/0550321375902795
states the assumptions on the genrator of a symmetry or supersymmetry in Section 2:
(i) it commutes with the S- …
- 45.7k
8
votes
The energy spectrum in quantum field theory
As the four components of the momentum vector commute, the right spectrum to consider is the joint spectrum of the momentum; the energy spectrum alone is far too degenerate. Because of Lorentz symmetr …
- 45.7k
1
vote
Energy spectrum, mass spectrum, and mass gap
The lack of a mass gap goes in all interesting cases together with the existence of a massless particle. These don't have a rest frame. See, e.g., the section ''What is the mass gap?'' in my theoretic …
- 45.7k
11
votes
1
answer
773
views
Landau poles in dimension <4?
It is well-known that QED and $\Phi_4^4$ quantum field theory have (in renormalized perturbation theory) a Landau pole and therefore are not asymptotically free. Is this specific to 4-dimensional QFT, …
- 45.7k
3
votes
Interpretation of an "interaction" term
In principle, yes, but only if the expectation value of $\phi$ is nonzero, so $\phi$ would immediately be shifted. Moreover, the result would be badly nonrenormalizable, so nobody is using such terms. …
- 45.7k
2
votes
Accepted
Anomalous magnetic moment of electron
g=2 comes from the Dirac equation, and is a relativistic effect. In the Pauli equation, it would have to be added by hand.
Radiation corrections give additional terms to the Dirac equation and modif …
- 45.7k
3
votes
Quantum harmonic oscillator
I think the analogy with the bowls is not really appropriate. If one thinks of things oscillating at each point in space, these oscillations are heavily correlated, due to the field equations.
Indep …
- 45.7k
1
vote
Conceptual quantum field theory
E. Zeidler, Quantum Field theory I Basics in Mathematics and Physics, Springer 2006. http://www.mis.mpg.de/zeidler/qft.html
is a book I highly recommend. It is the first volume of a sequence, of whic …
- 45.7k