Questions tagged [large-n]
The large-n tag has no usage guidance.
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Next-to-leading $1/N$ contributions to Feynman diagrams in large $N$
I want to understand $1/N$ contributions to quark bilinear operators $J(x)$ in large $N$, for instance, operators of the form $q\bar{q}$ or $\bar{q}\gamma^\mu q$. As pointed out by E. Witten, in the ...
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Why $N\to \infty$ limit implies $g_s \to 0$ in holographic QCD?
One basic difficulty in QCD is that it does not contain a small dimensionless quantity that would allow for perturbative calculation of low-energy observables.
A remarkable feature of holographic ...
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Subleading correction to the gluon propagator in large $N$ expansion
I was reading Callan, Coote and Gross' paper on 2-dimensional QCD, where they show that the model that 't Hooft proposes in his work indeed produces quark confinement. In section VIII, they analyze ...
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How does the matrix model simplify path integral?
While I'm reading the introduction of matrix models in Chapter 8 in Mariño's book(https://doi.org/10.1017/CBO9781107705968), I notice this description of matrix model:
We will begin by a drastic ...
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Question about large $N$ limit of CFT in the boundary
I read that in the limit of large $N$, the CFT on the boundary becomes classical. My question is if in such limit the physics in the bulk also becomes classical, or if we can still have a quantum ...
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What is the physical meaning of the large $N$ expansion?
I know about the $1/N$ expansion for some time. Apart from the fact that as Witten suggests, it can be the correct expansion parameter of QCD Baryons in the $1/N$ Expansion (in a parallel that he ...
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Physical interpretation of the asymptotics of partition function in string theory
I would like to understand the physical interpretation of the asymptotic expansion of a partition function. The QCD partition function with gauge group $SU(N)$ as $N$ is large has been shown by Gross ...
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Isn't AdS/CFT an end to String theory as a fundamental theory?
I start with the Large $N$ QCD paper by 't Hooft.
When 't Hooft published his paper on Large $N$ QCD it was clear why the string theory of hadrons due to Gabriele Veneziano could make sense. But at ...
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Relationship between multiplicity in the $k$-fold product of fundamentals and irrep dimension at large $N$
Equation 3.5 of this paper by Gross and Klebanov makes the following interesting claim.
Take a group $U(N)$, with $N$ large, and consider the reducible representation $\mathcal{H}_{fund}^{\otimes k}$ ...
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Does planar (or non-planar) ${\cal N}=4$ SYM contain bound states?
Does planar/large number of colors ${\cal N}=4$ SYM contain bound states at strong or weak coupling? Are there bound states in the non-planar limit at strong or weak coupling?
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What is the purpose and meaning of taking the 't Hooft parameter to infinity?
I am following Hong Liu's MIT 8.821 String Theory and Holographic Duality lectures. He starts discussing the large-$N$ expansion in the context of a hermitian matrix model described by the Lagrangian
$...
user242231
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Resources on calculation of beta function for $\mathrm{O}(N)$ model
Is there any useful introductory material about the calculation of the beta function in $\phi^4$ scalar theory and $O(N)$ model? I would also like to generalize this to the large-$N$ limit.
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Beta function in the large $N$ limit
I am currently studying Quantum Field Theory in the large $N$ limit (https://arxiv.org/abs/hep-th/9601080) and I am trying to understand how to calculate RG $β$-function
$N$ β-function" />
How can one ...
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$O(N)$ symmetry in three dimensions
Recently, In a research article on magnetism, I came across the term
"$O(N)$ symmetry for three dimensions with the limit $N->infinity$".
What does it mean? When I tried to search about ...
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How large is large $N$?
I once heard Lenny Susskind relate the question: "how many particles do you need in a box for the ideal gas law to 'pretty much' hold?" Obviously this question requires a notion of 'pretty ...
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