REVIEW
Multi-Instanton Calculus and Equivariant Cohomology
High Energy Physics - Theory · Submitted 12 Nov 2002 · 36 references
Pith's verdict: The sum-over-Young-diagram formulas are the real product and they check out at k=1,2; the derivation leans on an unproved localization theorem deferred to an in-preparation paper, which is a genuine but not fatal dependency.
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Referee report
The paper
The paper claims
Multi-instanton amplitudes in supersymmetric gauge theories are claimed to reduce to a finite sum over Young diagrams, each weighted by an explicit product of eigenvalues.
The reading
What carries the argument
The load-bearing device is a supersymmetric version of the equivariant localization formula, Eq. (2.17), in which the manifold is replaced by a supermanifold whose functions are differential forms and the exterior derivative by an odd vector field $Q^*$ with $tfrac12{Q^*,Q^*}=hatxi^*$, the even generator of the group action. The integral of an equivariantly closed form then equals $(-2pi)^{n/2}$ times a sum over the zeros of $Q^*$, each weighted by the inverse square root of the superdeterminant of $L_{x_0}=[Q^*,cdot]$. The second device is the rewriting of the ADHM action as $Q_epsilon$ of a single functional, so that the action vanishes at the critical points and the weight is one. The third is the character $chi=sum_i(-)^F e^{ilambda_i}$ of the linearized operator, reduced by algebra to a sum over the $2kN$ eigenvalues of the tangent space, which is then converted into a product over boxes; this is where the cancellations that would otherwise come from solving the ADHM constraints are automatically accounted for.
Extended reading notes
Core claim
The central claim is that the $k$-instanton partition function of an $SU(N)$ supersymmetric gauge theory is an explicit finite sum over $N$-tuples of Young diagrams with $k$ boxes in total. For pure $mathcal{N}=2$ theory the weight is $prod_{lambda,tildelambda}prod_{sin Y_lambda} 1/[E(s)(E(s)-epsilon)]$ with $E(s)=a_{lambda tildelambda}-epsilon_1 h(s)+epsilon_2(v(s)+1)$, where $h(s)$ and $v(s)$ count boxes to the right of and below the box $s$; adding $N_F$ fundamental hypermultiplets multiplies each box by $prod_f(phi(s)+m_f)$; and the $mathcal{N}=2^*$ case multiplies by $(E(s)-m)(E(s)-epsilon+m)$. In the $mathcal{N}=4$ limit $mto 0$ every weight becomes one, so $Z_k$ counts $N$-coloured partitions of $k$, giving $sum_k Z_k q^k=prod_{nge 1}(1-q^n)^{-N}$ and $F_k=Nsum_{dmid k}1/d$. The authors present this as a derivation rather than a fit: measure, constraints and correlators all follow from one BRST-exact action through localization, and the results for $k=1,2$ reproduce earlier computations.
Load-bearing premise
The whole derivation rests on the supersymmetric localization formula, Eq. (2.17), which the paper states without proof and defers to a companion paper listed as in preparation, and which extends a theorem proved for compact manifolds to a non-compact supermanifold whose fixed-point set is singular until the resolution parameter is switched on.
Editorial extensions
If this is right
- Instanton corrections to the Seiberg-Witten prepotential become a finite combinatorial sum for every winding number $k$ and every rank $N$, so coefficients can be extracted without solving the ADHM constraints explicitly.
- Adding fundamental hypermultiplets only multiplies each box weight by a flavour factor, so the matter sector is brought under the same computational control as the pure gauge sector.
- The $mathcal{N}=4$ case yields the Euler characteristic of the instanton moduli space and a generating function $prod_n(1-q^n)^{-N}$, matching the modular structure $ln|tau_2 eta(tau)^4|$ seen in the D3-brane effective action.
- Because the argument uses only the fixed-point character of a $Q$-exact action, the same machinery should apply to any moduli problem presented in ADHM-like matrix form.
Reading between the lines
- The paper uses a resolution parameter $zeta$ to smooth the small-instanton singularities, but the final sums over diagrams contain no $zeta$; making that independence explicit would be a clean internal consistency check the authors do not perform.
- The stated localization formula is a mathematical claim in its own right: a proof would be a theorem about equivariant cohomology of supermanifolds with non-compact or singular fixed-point sets, and would stand independently of any gauge theory application.
- Since only the character of the linearized operator enters, the same bookkeeping plausibly extends to quiver and orbifold gauge theories and to instantons on curved backgrounds, where the fixed-point combinatorics changes but the logic does not.
- The product-over-boxes form makes the large-$k$ asymptotics accessible by standard combinatorial means, which could turn the instanton expansion into a tool for probing the strong-coupling regime of the prepotential.
Original abstract
We present a systematic derivation of multi-instanton amplitudes in terms of ADHM equivariant cohomology. The results rely on a supersymmetric formulation of the localization formula for equivariant forms. We examine the cases of N=4 and N=2 gauge theories with adjoint and fundamental matter.
The compiled record
The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
The abstract, sentence by sentence
We present a systematic derivation of multi-instanton amplitudes in terms of ADHM equivariant cohomology. The results rely on a supersymmetric formulation of the localization formula for equivariant forms. We examine the cases of N=4 and N=2 gauge theories with adjoint and fundamental matter.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We present a systematic derivation of multi-instanton amplitudes in terms of ADHM equivariant cohomology. | contribution 1.00 | 0.95 | 0.71 | asserted 1.00 |
| s1 | The results rely on a supersymmetric formulation of the localization formula for equivariant forms. | method 1.00 | 0.61 | 0.09 | asserted 1.00 |
| s2 | We examine the cases of N=4 and N=2 gauge theories with adjoint and fundamental matter. | contribution 0.98 | 0.88 | 0.07 | asserted 0.94 |
What was examined, and what was not
- arXiv listing abstract v4
- full text
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- references and citing sentences
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- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
Figures
Figures reproduced from arXiv:hep-th/0211108 by the authors.
References
How later papers used it
117 later papers cite it
3 later papers by other authors are listed below: 2 used its method or tool and 1 compared its own results with it. 1 more paper by the same authors is listed: 1 used its method or tool.
Uses its method or tool 3 of 27 papers with this label · 1 by the same authors
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Computed the vortex partition function in N=(2,2) super Yang-Mills theories by the equivariant localization formula for supersymmetric systems.
Localization of Vortex Partition Functions in $\mathcal{N}=(2,2) $ Super Yang-Mills theory (2011) · 1.00 · paraphrased: the licence does not allow quoting
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Gave the vortex partition function for (N) gauge theory with N fundamental chiral multiplets by applying this paper's localization formula.
Vortex counting from field theory (2012) · 0.99 · paraphrased: the licence does not allow quoting
By the same authors
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Used the refined topological vertex together with this paper to write the instanton partition function as a sum with coefficients of the Nekrasov partition function.
Seiberg-Witten theory as a Fermi gas (2016) (same authors) · 0.99 · paraphrased: the licence does not allow quoting
Compares with it 1 of 5 papers with this label
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Compared with eqn.(3.26) of this paper, with a recent modification in the hypermultiplet mass contribution, and found that the sinh arguments in the numerator of its own N=2* partition function are shifted by m+ϵ_R.
On instantons as Kaluza-Klein modes of M5-branes (2011) · 0.98 · paraphrased: the licence does not allow quoting
How the literature uses it
115 arXiv papers cite this in 171 sentences
Papers citing it · 108 sentences without a confident label
Builds on it 2 papers
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The instanton partition function is [equation] By Equation [ref] and the corresponding expression for the Nekrasov partition function of $U(r)$ gauge theory on $ℝ^4$ with $N$ fundamental hypermultiplets of masses $μ_1, …, μ_N$ [ref] [equation] we get [box=]multline ^N, inst_X_k(ε_1, ε_2, a⃗,μ⃗; , ξ⃗ ) =∑_v⃗∈_w⃗ ξ⃗^ v⃗ ∑_v⃗ ^1/2 ∑_α=1^r v⃗_α·Cv⃗_α ∏_s=1^N ∏_α=1^r ∏_n=1^k-1 ℓ^(n)_v⃗_α(ε_1^(n), ε_2^(n), a_α+μ_s )/∏_α,β=1^r ∏_n=1^k-1 ℓ^(n)_v⃗_βα(ε_1^(n), ε_2^(n), a_βα ) ∏_i=1^k ^N, inst_^2 (ε_1^(i), ε_2^(i), a⃗^(i),μ⃗; ) .
Framed sheaves on root stacks and supersymmetric gauge theories on ALE spaces · Instanton partition function · 0.89
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In the case with adjoint hypermultiplet instead of ([ref]) one starts with the (super) character [ref] χ= (1-T_m)× ∑_α,β=1^N e_βe_α^-1 {∑_s∈Y_α(T_1^-l_β(s)T_2^a_α(s)+1)+∑_s∈Y_β(T_1^l_α(s)+1T_2^-a_β(s))}.
Non-perturbative aspects of gauge and string theories and their holographic relations · ADHM construction · 0.84
Uses its method or tool 28 papers
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The proof will rely on multi instanton formulae obtained via localization [ref] .
Multi instanton tests of holography · Introduction and Summary · 1.00
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The instanton partition function follows from the localization formula [ref] Z_inst =∑_Y q^|Y| ∏_u,v=1^N Z_∅,Y_v(μ̅_u-a_v ) Z_Y_u,∅(a_u-μ_v )Z_Y_u,Y_v(a_u-a_v)
Exact results in N=2 gauge theories · The gauge theory on $^2$ · 0.91
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To linear order in $δT$ one gets [equation] In order to perform the integration over the moduli space and obtain explicit results, we exploit the localization formula and adopt Nekrasov's approach to the multi-instanton calculus Ref.s [ref] (see also Ref.s [ref] ).
Non-perturbative gauge/gravity correspondence in N=2 theories · The non-perturbative $t$ profile · 1.00
Compares with it 4 papers
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The corresponding bra is given by [equation] Now, it can be checked that [equation] Therefore, [equation] which is indeed the one-instanton contribution of Nekrasov's partition function [ref] calculated from the geometry of the one-instanton moduli space.
The ABCDEFG of Instantons and W-algebras · $A_n$ · 0.86
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Comparing with eqn.(3.26) of [ref] , with a recent modification in the hypermultiplet mass contribution [ref] , we find that the $sinh$ arguments in the numerator of the $𝒩=2^∗$ partition function are shifted by $m+ϵ_R$.
On instantons as Kaluza-Klein modes of M5-branes · The index · 0.98
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The action in [ref] contains the quartic terms of $a'_m, χ_a$ and the quadratic term of $D^c̃$ which are absent in our action.
N=4 Instanton Calculus in Omega and R-R Backgrounds · Conclusions and Discussion · 1.00
Cites it as background 20 papers
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Recently Alday Gaotto and Tachikawa [ref] have found a very remarkable relation between generalized partition functions [ref] in certain classes of $N=2$ conformal $SU(2)$ quiver gauge theories [ref] (see [ref] for instanton counting in quiver theories) and correlation functions of 2d Liouville theory on Riemann surfaces.
Recursion relations in CFT and N=2 SYM theory · Introduction · 0.81
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This line of research is founded on the so called AGT correspondence [ref] which relates the results of localization for the partition functions of a $N=2$ supersymmetric quiver gauge theories [ref] with certain correlators of the Liouville CFT.
Post Newtonian emission of gravitational waves from binary systems: a gauge theory perspective · Introduction · 0.85
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The instanton part of the partition function [ref] of this theory can be represented as [ref] [equation] where $Y⃗$ is a pair of Young diagrams $Y⃗=(Y_1,Y_2)$ and $|Y⃗|$ is the total number of boxes.
Recursion relation for instanton counting for $SU(2)$ ${\cal N}=2$ SYM in NS limit of $\Omega$ background · The deformed prepotential in the NS limit · 0.81
Discussion
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