REVIEW
Konishi operator at intermediate coupling
High Energy Physics - Theory · Submitted 25 Jun 2010 · 75 references
Pith's verdict: A solid, honest numerical push on the Konishi TBA — but the λ_cr > 5300 headline is one fit choice, not a bound, and the author knows it.
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Referee report
The paper
The paper claims
Solving the mirror thermodynamic Bethe ansatz numerically up to 't Hooft coupling $2046$, Frolov argues that the Konishi operator's first critical coupling lies above $5300$ — far beyond the earlier estimate of $774$ — and that its strong-c
The reading
What carries the argument
The load-bearing object is the set of simplified and hybrid TBA equations for two-particle $sl(2)$ states, which determine the $Y$-functions $Y_{M|w}$, $Y_{M|vw}$, $Y_pm$ and $Y_Q$ together with the exact Bethe equation for the root $w$; the Konishi energy is $E_K = 2 + 2sqrt{1+4g^2sin^2(p/2)} - sum_Q int frac{dtilde p}{2pi} log(1+Y_Q)$. Because the critical coupling is where particular $Y$-functions at $u=0$ vanish ($Y_2$, $Y_pm$, $Y_{1|vw}+1$), the numerics can address the existence of critical values directly rather than by analogy with the asymptotic solution. The technical enabler is a new representation of the BES dressing phase $Theta$ as a one-dimensional integral over $t in [0,1]$ of elliptic $Pi$-functions times $logGamma$ factors, valid in all four string/mirror kinematic regions, plus companion $Psi$-function integrals; this is what makes solving up to $lambda approx 2046$ practical.
Extended reading notes
Core claim
The paper's central claim is that the excited-state TBA equations for Konishi-like states stay valid far beyond the coupling at which the large-$J$ asymptotic $Y$-functions would place a critical point. Solving the equations up to $g=7.2$ and extrapolating the vanishing of $Y_2(0,g)$, $Y_pm(0,g)$ and $Y_{1|vw}(0,g)+1$ gives $g_{rm cr}^{(1)} > 11.6$, that is $lambda_{rm cr}^{(1)} > 5300$ and probably $5300 < lambda_{rm cr}^{(1)} < 5700$, against the earlier estimate $lambda_{rm cr}^{(1)} approx 774$. On the way the data pin down the large-$lambda$ series: imposing $c_{-1}=2$, $c_0=0$, $c_1=2$, $c_2=0$, the remaining coefficients stabilise around $c_3 approx -3.26$, $c_4 approx 2.53$, $c_5 approx 4.03$, giving $E_K = 2lambda^{1/4} + 2/lambda^{1/4} - 3.26/lambda^{3/4} + 2.53/lambda + 4.03/lambda^{5/4}$. That function fits the numerical data as well as the alternative with all even coefficients set to zero, but it has a nonvanishing $c_4$, so the expansion appears to run in powers of $1/lambda^{1/4}$ rather than $1/sqrt{lambda}$.
Load-bearing premise
The fit assumes the large-$lambda$ expansion contains only powers of $1/lambda^{1/4}$ with no $loglambda$ terms, and that exponentially small corrections are already negligible at $lambda lesssim 2046$; the author notes that a $0.0002$ precision floor could by itself account for the nonzero $c_4$.
Editorial extensions
If this is right
- The first critical coupling of the Konishi operator is $lambda_{rm cr}^{(1)} > 5300$, most likely in the window $5300$–$5700$, rather than the $approx 774$ suggested by the large-$J$ asymptotic solution.
- The strong-coupling expansion of the Konishi energy is in powers of $1/lambda^{1/4}$ with $c_{-1}=c_1=2$, $c_0=c_2=0$ and $c_4 approx 2.53$ nonzero, so the earlier prediction that only powers of $1/sqrt{lambda}$ appear is not confirmed.
- The computed energies agree with the earlier canonical-TBA results to about $0.0015$ across the overlapping range, supporting the equivalence of the two TBA formulations for Konishi-like states.
- The $Y_Q$ contributions to the energy grow nearly linearly with $g$ over the range studied, which raises the possibility that the exact Bethe root asymptotes to a constant below $2$ and that critical values are absent altogether.
Reading between the lines
- If the near-linear growth of the $Y_Q$ energy contribution persists, the exact Bethe root would settle below $2$ while the flat-space string spectrum is still recovered from the Bethe–Yang equations, so either the growth saturates at larger $g$ or the route from TBA to the flat-space spectrum needs rethinking.
- A nonzero $c_4$ would break the pattern suggested by the free-fermion model of the $su(1|1)$ sector, where the expansion is in $1/lambda^{1/4}$ only up to an overall factor; comparing the fitted $c_4$ against the next order of the semiclassical string expansion would discriminate between the two pictures.
- The new elliptic-integral form of the dressing phase, combined with a Newton-method solver of the kind used for the Hubbard model, should make $lambda approx 5000$ reachable and turn the extrapolated critical coupling into a measured one.
- If no critical value exists for Konishi, the equations would remain valid at all couplings, which changes what wrapping corrections mean for short operators and would make the intermediate-coupling regime the generic one rather than a transient.
Original abstract
TBA equations for two-particle states from the sl(2) sector proposed by Arutyunov, Suzuki and the author are solved numerically for the Konishi operator descendent up to 't Hooft's coupling lambda ~ 2046. The data obtained is used to analyze the properties of Y-functions and address the issue of the existence of the critical values of the coupling. In addition we find a new integral representation for the BES dressing phase which substantially reduces the computational time.
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
TBA equations for two-particle states from the sl(2) sector proposed by Arutyunov, Suzuki and the author are solved numerically for the Konishi operator descendent up to 't Hooft's coupling lambda ~ 2046. The data obtained is used to analyze the properties of Y-functions and address the issue of the existence of the critical values of the coupling. In addition we find a new integral representation for the BES dressing phase which substantially reduces the computational time.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | TBA equations for two-particle states from the sl(2) sector proposed by Arutyunov, Suzuki and the author are solved numerically for the Konishi operator descendent up to 't Hooft's coupling lambda ~ 2046. | method 0.50 | 0.84 | 0.25 | asserted 1.00 |
| s1 | The data obtained is used to analyze the properties of Y-functions and address the issue of the existence of the critical values of the coupling. | contribution 0.49 | 0.92 | 0.18 | asserted 0.98 |
| s2 | In addition we find a new integral representation for the BES dressing phase which substantially reduces the computational time. | contribution 0.73 | 0.96 | 0.12 | asserted 1.00 |
What was examined, and what was not
- arXiv listing abstract v2
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- P abstract
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Figures
Figures reproduced from arXiv:1006.5032 by the authors.
References
How later papers used it
47 later papers cite it
2 later papers by other authors are listed below: 2 used its method or tool. 1 more paper by the same authors is listed: 1 used its method or tool.
Uses its method or tool 3 papers · 1 by the same authors
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Used a method similar to the one used in this paper, with the advantage of easily keeping track of the explicit shape of the Y-functions.
The spectrum of tachyons in AdS/CFT (2013) · 0.95 · paraphrased: the licence does not allow quoting
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Found the representation of the dressing phase as presented in this paper most convenient in solving the equation numerically.
Lifting asymptotic degeneracies with the Mirror TBA (2011) · 0.99 · paraphrased: the licence does not allow quoting
By the same authors
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Used the same code as this paper, with minor modifications, for the J=4, n=1 state beyond its (sub)critical value.
Scaling dimensions from the mirror TBA (2012) (same authors) · 0.99 · paraphrased: the licence does not allow quoting
How the literature uses it
47 arXiv papers cite this in 71 sentences
Papers citing it · 48 sentences without a confident label
Uses its method or tool 3 papers
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The same code as in [ref] is used here with minor modifications for the $J=4,n=1$ state beyond its (sub)critical value.
Scaling dimensions from the mirror TBA · Introduction and Summary · 0.99
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This method is similar to the one used in [ref] , and has the advantage that we can easily keep track of the explicit shape of the Y-functions.
The spectrum of tachyons in AdS/CFT · Algorithm for integration · 0.95
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In solving ([ref]) numerically, the representation of the dressing phase as presented in [ref] is most convenient.
Lifting asymptotic degeneracies with the Mirror TBA · Two explicit states · 0.99
Uses its data or values 3 papers
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Spectral data on the leading and sub-leading Regge trajectories is readily available for the initial few values of the spin-label $ℓ$ [ref] .
Unmixing sub-leading Regge trajectories of $\mathcal{N} = 4$ Super-Yang-Mills · CFT-data and Regge trajectories · 0.80
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Also, fitting the known numerical results [ref] with a diagonal Padé approximant, we were able to fix the 6-loop energy with \(5%\) confidence.
Six-loop Konishi anomalous dimension from the Y-system · Weak coupling expansion · 0.80
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For extremely large $λ$'s the numerical solutions become very slow, the largest value of $λ$ reached up to now is about $2000$ [ref] .
Quantum folded string and integrability: from finite size effects to Konishi dimension · Introduction · 0.94
Compares with it 9 papers
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Eq ([ref]) produces .Δ^classical+Δ^1-loop|_S=2,J=2=2λ^1/4 +2/λ^1/4 in the perfect agreement with the Y-system prediction of [ref] [It is also compatible with the recent numerics with slightly higher precision [ref] .].
Quantum folded string and integrability: from finite size effects to Konishi dimension · Short operator limit · 0.99
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The results of this numerical study are in perfect correspondence with the results obtained in [ref] from TBA and thus confirm the validity of our FiNLIE.
Solving the AdS/CFT Y-system · Introduction · 0.97
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The whole process took about $20$ seconds on a usual laptop (see Fig. [ref]), producing the value $Δ=4.4188599$, consistent with the best TBA estimates [ref] .
Quantum Spectral Curve and the Numerical Solution of the Spectral Problem in AdS5/CFT4 · Implementation for the $sl(2)$ Sector and Comparison with Existing Data · 0.99
Cites it as background 4 papers
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These equations were proposed in [ref] , following the discovery of the Y-system [ref] , and passed a number of important checks [ref] .
Solving the AdS/CFT Y-system · Equivalence of FiNLIE to the TBA equations · 0.97
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For $=4$ SYM, the integrability has been used as a powerful tool to interpolate between strong and weak coupling, where one can see the perturbative behavior of the gauge theory morph into the stringy behavior expected from the AdS/CFT conjecture [ref] .
Superspace calculation of the four-loop spectrum in N=6 supersymmetric Chern-Simons theories · Introduction · 0.94
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Speculation on the existence of such critical values in the context of the TBA for $𝒩=4$ SYM was presented in [ref] .
Exploring the spectrum of planar $AdS_4/CFT_3$ at finite coupling · Study of the TBA function Y1,0 · 0.84
What it cites · 65 sentences without a confident label
Contests 2 papers
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Thus, the coefficient $c_4$ of the term $1/$ does not vanish, and we cannot confirm the prediction of [ref] that up to an overall factor of $√()$ the large $$ expansion of the Konishi state energy is a series in $1/√()$.
Exact AdS/CFT spectrum: Konishi dimension at any coupling · Introduction · contest 0.74
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Third, it makes a new prediction which disagrees with the semiclassical consideration in [ref] that the first nonvanishing subleading coefficient is also equal to 2.
Quantum strings in AdS_5 x S^5: strong-coupling corrections to dimension of Konishi operator · Introduction · contest 0.77
Builds on 9 papers
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The analysis in [ref] was then extended to prove the agreement analytically first for the Konishi operator [ref] , and then for an arbitrary twist-two operator [ref] reproducing the results in [ref] .[The five-loop computations in [ref] were based on [ref] where the four-loop anomalous dimension of the Konishi operator was computed and shown to agree with the direct field theory result [ref] .
Wrapping at four loops in N=4 SYM · Introduction · 0.84
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The analysis in [ref] was then extended to prove the agreement analytically first for the Konishi operator [ref] , and then for an arbitrary twist-two operator [ref] reproducing the results in [ref] .[The five-loop computations in [ref] were based on [ref] where the four-loop anomalous dimension of the Konishi operator was computed and shown to agree with the direct field theory result [ref] .
Four-loop perturbative Konishi from strings and finite size effects for multiparticle states · Introduction · 0.84
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The analysis in [ref] was then extended to prove the agreement analytically first for the Konishi operator [ref] , and then for an arbitrary twist-two operator [ref] reproducing the results in [ref] .[The five-loop computations in [ref] were based on [ref] where the four-loop anomalous dimension of the Konishi operator was computed and shown to agree with the direct field theory result [ref] .
The Four-Loop Konishi in N=4 SYM · Introduction · 0.84
Uses the method or tool of 3 papers
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We solve numerically the excited states TBA equations [ref] for the Konishi operator up to 't Hooft's coupling $λ≈2046$, and use the data obtained to analyze the behavior of Y-functions.
Exploring the mirror TBA · Introduction · 0.95
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One possible improvement would be to use Newton's method for solving the TBA equations as it was done for the Hubbard model in [ref] .
TBA Equations of 1D Hubbard Model and High-Temperature Expansion · Conclusion · 0.99
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We used in our computation a new integral representation for the BES dressing phase [ref] which significantly reduces the computational time.
Transcendentality and Crossing · Introduction · 1.00
Uses data or values from 1 paper
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Analyzing the results obtained, the authors of [ref] found the following fitting function for the Konishi state energy or, equivalently, for the conformal dimension of the dual Konishi operator E_K^GKV()=√()(2.0004+1.988/ √()-2.60/+6.2/^3/2) .
Exact AdS/CFT spectrum: Konishi dimension at any coupling · Introduction · 0.95
Compares with 7 papers
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These terms are known to appear in the strong coupling expansion of the Bethe-Yang equations [ref] .] we found convincingly that the first nontrivial subleading coefficient $c_1$ is equal to 2 and the coefficient $c_2$ vanishes in agreement with the previous prediction [ref] .
Exact AdS/CFT spectrum: Konishi dimension at any coupling · Conclusion · 0.80
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These terms are known to appear in the strong coupling expansion of the Bethe-Yang equations [ref] .] we found convincingly that the first nontrivial subleading coefficient $c_1$ is equal to 2 and the coefficient $c_2$ vanishes in agreement with the previous prediction [ref] .
On the strong coupling expansion in the su(1|1) sector of N=4 SYM · Conclusion · 0.80
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These terms are known to appear in the strong coupling expansion of the Bethe-Yang equations [ref] .] we found convincingly that the first nontrivial subleading coefficient $c_1$ is equal to 2 and the coefficient $c_2$ vanishes in agreement with the previous prediction [ref] .
Konishi at strong coupling from ABE · Conclusion · 0.80
Cites as background 8 papers
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It is known that at large values of 't Hooft's coupling the energy of the Konishi state can be expanded in an asymptotic series in powers of $1/ √()$ asexp E_K()=2 √()+c_0+c_1/ √()+c_2/√()+c_3/^3/4+c_4/+c_5/^5/4+ ⋯ , where the leading $2 √()$ behavior follows from the string spectrum in flat space [ref] , and can be reproduced from the asymptotic Bethe ansatz [ref] .
Bethe Ansatz for Quantum Strings · Konishi state energy · 0.89
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It is known that at large values of 't Hooft's coupling the energy of the Konishi state can be expanded in an asymptotic series in powers of $1/ √()$ asexp E_K()=2 √()+c_0+c_1/ √()+c_2/√()+c_3/^3/4+c_4/+c_5/^5/4+ ⋯ , where the leading $2 √()$ behavior follows from the string spectrum in flat space [ref] , and can be reproduced from the asymptotic Bethe ansatz [ref] .
Gauge Theory Correlators from Non-Critical String Theory · Konishi state energy · 0.89
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The large $λ$ perturbative expansion of the light-cone string sigma model (see [ref] for a review) allows one to have any of the coefficients $c_i$ nonvanishing.
Foundations of the AdS_5 x S^5 Superstring. Part I · Konishi state energy · 0.91
Discussion
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