The yang-mills tag has no wiki summary.
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Are Gribov copies responsible for the observed Mass-gap and color confinement properties of Pure Yang-Mills Theory?
New solutions to the existing problems are presented by the quantum mechanics and Einstein's theory of special relativity when treated together. The creation of particle/anti-particle pairs by quantum ...
3
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1answer
59 views
Four-gauge-boson vertex in non-Abelian gauge theories
In Peskin & Schroeder's book page 524, the following diagram is calculated for the gauge boson self-energy in order $g^2$:
In dimensional regularization, its contribution is given by
...
4
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1answer
144 views
Yang-Mills instanton
How can instanton solution to Yang-Mills theory with gauge group $SU(3)$ or $SU(N)$ be obtained? For $SU(2)$ it is explained in textbooks but what about more general color gauge groups?
EDIT: How ...
4
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1answer
81 views
Some questions about Ward-Takahashi Identity
I'm a learner of Peskin and Schroeder's textbook of quantum field theory.
I have proceeded to Ward-Takahashi identity and have one question when I look for Wikipedia for reference.
The following is ...
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Some Korean researchers saying that they solved Yang-mill existence and mass gap problem
Today, Korean media is reporting that a team of South Korean researchers solved Yang-Mill existence and mass gap problem. Did anyone outside Korea even notice this? I was not able to notice anything ...
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sigma model on $S^1 \times S^3$
In arXiv:1207.3497 - 4D partition function on $S^1 \times S^3$ and 2D Yang-Mills with nonzero area, Yuji Tachikawa explains the partition function for an 4d $\mathcal{N}=2$ sigma model on $S^3 \times ...
13
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1answer
212 views
Spontaneous breaking of Lorentz invariance in gauge theories
I was browsing through the hep-th arXiv and came across this article:
Spontaneous Lorentz Violation in Gauge Theories. A. P. Balachandran, S. Vaidya. arXiv:1302.3406 [hep-th]. (Submitted on 14 ...
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1answer
131 views
Frasca's mapping of classical Yang-Mills to $\phi^4$ theory
I recently came across an article on the arXiv 0709.2042 written by Marco Frasca, where he provides a mapping between classical Yang-Mills theory to $\phi^4$ theory. Has his idea been fruitful in ...
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Good Books on Gauge Theory [duplicate]
Possible Duplicate:
Comprehensive book on group theory for physicists?
I'm having a hard time trying to get my head around the fundamentals of gauge theory. I've taken classes in QFT and ...
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86 views
Yang-Mills Coulomb Gauge
My Question is how to explicitly move into the "Coulomb gauge" in Yang-Mills theory.
Using the answer provided by QMechanic, one can move into the "temporal gauge" for Yang-Mills fields: Gauge fixing ...
13
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1answer
402 views
Multi-loop beta function of gauge theory (*without* Feynman diagrams)
I would like to point to the beautiful section 4.3 (page 42) of these lecture notes. I think this is the most educative exposition I have ever seen anywhere about Yang-Mill's beta function. What I ...
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76 views
Glueball mass in non-abelian Yang Mills theory
How can the glueball mass be calculated in Yang Mills theory?
2
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1answer
95 views
Yang Mills Hamiltonian
Do you know why in the quantization of SU(2) Yang Mills Gauge Theory, it is always chosen the Weyl (temporal) gauge to derive the Hamiltonian?
Is it possible to fix another gauge?
5
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1answer
329 views
Faddeev-Popov ghost propagator in canonical quantization
Obtaining the propagator for the Faddeev-Popov (FP) ghosts from the path integral language is straightforward. It is simply
$$\langle T(c(x) \bar c(y))\rangle~=~\int\frac{d^4 p}{(2\pi)^4}\frac{i ...
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4answers
145 views
Cubic term in gauge theories
In ordinary classical gauge theories the term $-\frac{1}{2}\mathrm{Tr}(F_{\mu\nu}F^{\mu\nu})=-\frac{1}{4}F^a_{\mu\nu}F_a^{\mu\nu}$ in the Lagrangian is completely natural. A somehow rare term would be ...
4
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2answers
146 views
Kugo and Ojima's Canonical Formulation of Yang-Mills using BRST
I am trying to study the canonical formulation of Yang-Mills theories so that I have direct access to the $n$-particle of the theory (i.e. the Hilbert Space). To that end, I am following Kugo and ...
5
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2answers
199 views
Can auxiliary fields be thought of as Lagrange multipliers?
In the BRST formalism of gauge theories, the Lautrup-Nakanishi field $B^a(x)$ appears as an auxiliary variable
$$\mathcal{L}_\text{BRST}=-\frac{1}{4}F_{\mu\nu}^a F^{a\,\mu\nu}+\frac{1}{2}\xi B^a B^a + ...
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SU(2) critical point and volume dependence
I am doing multi-dimensional plots of $\beta_j$ for SU(2) for infinite volume to understand the flow behavior and I was wondering, before I go too much further, if anyone knew off the top of their ...
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1answer
99 views
Relating theta_QCD to neutron EDM
How do I relate the topological $\theta_\text{QCD}$ parameter to the electric dipole moment (EDM) of the neutron?
I am very familiar with chiral perturbation theory. I just need to know how to take ...
2
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1answer
204 views
Wilson loops and gauge invariant operators (Part 2)
These questions are sort of a continuation of this previous question.
I would like to know of the proof/reference to the fact that in a pure gauge theory Wilson loops are all the possible gauge ...
5
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3answers
355 views
Gauge fixing choice for the gauge field $A_0$
In many situations, I have seen that the the author makes a gauge choice $A_0=0$, e.g. Manton in his paper on the force between the 't Hooft Polyakov monopole.
Please can you provide me a ...
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1answer
252 views
Wilson loops and gauge invariant operators (Part 1)
I guess the Hilbert space of the theory is precisely the space of all gauge invariant operators (mod equations of motion..as pointed out in the answers)
Is it possible that in a gauge theory the ...
5
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3answers
245 views
Could general relativity and gauge theories in principle be covered in one course?
It's always nice to point out the structural similarieties between (semi-)Riemannian geometry and gauge field theories alla Classical yang Mills theories. Nevertheless, I feel the relation between the ...
2
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1answer
209 views
Spontaneous symmetry breaking and 't Hooft and Polyakov monopoles
What is spontaneous symmetry breaking from a classical point of view. Could you give some examples, using classical systems.I am studying about the 't Hooft and Polyakov magnetic monopoles solutions, ...
3
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1answer
247 views
Gauge-invariant field strength term in Yang-Mills Lagrangian
I am reading the chapter of non-abelian gauge invariance from Peskin and Schroeder. Why is the term $-\frac{1}{4}(L_{\mu\nu}^i)^{2} $ gauge invariant?
5
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What is Motivic mathematics and how is it used in physics?
In a few videos I've seen where he discusses the new approach to calculating the super Yang Mills scattering amplitudes, Nima Arkani-Hamed sometimes alludes to the use of Motivic methods as being ...
3
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2answers
326 views
The Faddeev-Popov Lagrangian
This is a non-abelian continuation of this QED question.
The Lagrangian for a non-abelian gauge theory with gauge group $G$, and with fermion fields and ghost fields included is given by
$$
...
3
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1answer
105 views
Supergroup action on $AdS_5XS^5$
In the context of the AdS/CFT correspondence I was trying to understand how the symmetry group of the underlying space $AdS_5 X S^5$ comes out to be the supergroup $SU(2,2|4)$. I can see how the ...
6
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1answer
200 views
Reference for the ${\cal N}=3$ Chern-Simons Lagrangian at general $N_c$, $N_f$
I was wondering if someone could give me a reference where someone has explicitly written the Lagrangian for ${\cal N}=3$ $SU(N_c)$ Chern-Simons theory coupled to $N_f$ fundamental hypermultiplets.
...
6
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4answers
587 views
What's the distinctions between Yang-Mills theory and QCD?
So Yang-Mills theory is a non-abelian gauge theory, and we used a lot in QCD calculation.
But what are the distinctions between Yang-Mills theory and QCD?
And distinctions between supersymmetric ...
5
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1answer
230 views
What are the limitations of the superspace formalism?
Just from reading this slightly technical introduction to supersymmetry and watching these Lenny Susskind lectures, I thought that the Lagrangean of any "reasonable" supersymmetric theory can always ...
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1answer
201 views
A certain gluon scattering amplitude
I am stuck with this process of calculating the tree-level scattering amplitude of two positive helicity (+) gluons of momentum say $p_1$ and $p_2$ scattering into two gluons of negative (-) helicity ...
7
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1answer
25 views
Low-energy gluodynamics as a string
Does anyone know of a (most likely heuristic) derivation of the use of the string sigma model action to model the soft gluonic interactions between color charges? I'm familiar with the classic ...
6
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1answer
80 views
Some more questions about the BCFW reduction
This question is a continuation of this previous question of mine and I am continuing with the same notation.
One claims that one can actually split this $n$-gluon amplitude such that there is just ...
4
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1answer
67 views
Colour decomposition of $n-$gluon tree amplitude
I have here a $SU(N_c)$ Yang-Mill's theory and let the index $i$, label the $n$-gluons, and $\{k_i, \lambda_i, a_i\}$ be its momenta, helicity and colour index and $\cal{A}_n^{tree/1-loop}(\{k_i, ...
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1answer
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SU(2) yang-mills EOM
I'm just playing around tonight trying to better myself, but I'm having trouble with some indices on my yang-mills lagrangian. I have a gauge group $SU(2)$ and a field strength tensor
$$ ...
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1answer
168 views
Derivation of the effective potential between a quark and an anti-quark
Typically in particle physics books (not in QFT books!) I have often seen this statement that the potential between a heavy quark and its anti-quark can be "empirically" represented as $V(r) = ...
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2answers
90 views
Nonabelian gauge theories and range of the corresponding force
Do all nonabelian gauge theories produce short range force?
5
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Some questions about Wilson loops
Let $G$ be the gauge group whose Yang-Mill's theory one is looking at and $A$ be its connection and $C$ be a loop in the space-time and $R$ be a finite-dimensional representation of the gauge group ...
2
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1answer
263 views
Feynman rule 4-point vertex WW -> ZZ
I am looking for the Feynman rule of the 4-point gauge boson interaction of W+ W- -> Z Z. I am guessing it looks like the Yang Mills 4-point vertex for gluons, but with helicity included.
Equation ...
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88 views
Is the axial gauge with a $\xi$ term useful in Yang-Mills theory?
i) Do people use axial gauge with a $\xi$ term? When $\xi\neq 0$, ghosts do not decouple, but maybe it's still useful?
ii) Is it proved that the term $\frac 1 {2\xi}(n.A)^2$ in the Lagrangian does ...
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2answers
282 views
Wilson/Polyakov loops in Weinberg's QFT books
I wanted to know if the discussion on Wilson loops and Polyakov loops (and their relationship to confinement and asymptotic freedom) is present in the three volumes of Weinberg's QFT books but in some ...
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1answer
154 views
What is a “free” non-Abelian Yang-Mill's theory?
I hope this question will not be closed down as something completely trivial!
I did not think about this question till in recent past I came across papers which seemed to write down pretty much ...
3
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1answer
113 views
Unconstrained action in Yang-Mills theory
Is there any gauge in which Yang-Mills theory (4d, non-SUSY) can be written as a local action containing only the propagating modes?
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1answer
86 views
What evidence do we have for S-duality in N=4 Super-Yang-Mills?
Do we have anything resembling a proof*? Or is it just a collection of "coincidences"?
Also, do we have evidence from lattice gauge theory computations?
*Of course I'm not talking about a proof in ...
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2answers
172 views
How to prove quantum N=4 Super-Yang-Mills is superconformal?
I'm especially interested in elegant illuminating proofs which don't involve a lot of straightforward technical computations
Also, does a non-perturbative proof exist?
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1answer
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What makes background gauge field quantization work?
[Again I am unsure as to whether this is appropriate for this site since this is again from standard graduate text-books and not research level. Please do not answer the question if you think that ...
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3answers
206 views
Which exact solutions of the classical Yang-Mills equations are known?
I'm interested in the pure gauge (no matter fields) case on Minkowski spacetime with simple gauge groups.
It would be nice if someone can find a review article discussing all such solutions
EDIT: I ...
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2answers
130 views
Does 4D N = 3 supersymmetry exist?
Steven Weinberg's book "The Quantum Theory of Fields", volume 3, page 46 gives the following argument against N = 3 supersymmetry:
"For global N = 4 supersymmetry there is just one supermultiplet ... ...
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1answer
185 views
Lattice Yang-Mills
I have often heard statements like, Continuum limit of Lattice Yang-Mills doesnot exist in dimensions higher then four. Is there a neat way to see this? or could some one point me to some relevant ...
