REVIEW
Two loops in eleven dimensions
High Energy Physics - Theory · Submitted 6 Oct 1999 · 23 references
Pith's verdict: A real two-loop computation with a genuinely new moduli-space technique; the headline coefficient is solid, but two of its constants are fixed by consistency rather than computed.
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Referee report
The paper
The paper claims
The two-loop four-graviton amplitude of eleven-dimensional supergravity on a two-torus fixes the exact coefficient of the $D^4R^4$ term in the effective action, matching known string terms and predicting two-loop and D-instanton corrections
The reading
What carries the argument
The load-bearing device is a change of variables from the three Schwinger parameters of the two-loop integral to the volume $V$ and complex structure $��$ of an auxiliary torus $��T^2$, with $��_1=��/(��+��)$, $��_2=��{��}/(��+��)$ and $V=l_{11}^3��{��}$. This turns the integrand into a sum over maps of $��T^2$ into the compactification torus $T^2$ and exposes an $SL(2,��)$ action. The integration runs over the fundamental domain of $��_0(2)$, which is three copies of the standard fundamental domain. Boundary regions classify the divergences: $V����$ gives the primitive $��^8$ divergence, $��_2����$ and its images give the one-loop subdivergences, and non-degenerate orbits give the finite modular-invariant piece. Poisson resummation from Kaluza-Klein modes to winding numbers is what makes the orbit classification possible.
Extended reading notes
Core claim
The central result is Eq. (5.1), an exact expression for the renormalized two-loop contribution to the $D^4R^4$ term of the effective action. The $��$-dependent part is a non-holomorphic Eisenstein series $E_{5/2}(��,��)$; its large-$��_2$ expansion contains a tree-level term, a two-loop term and an infinite series of exponentially suppressed D-instanton terms. The $��$-independent piece matches the one-loop supergravity calculation, and the whole structure is consistent with type IIA/IIB equality through two loops. The paper also argues that the leading two-loop divergence cannot contribute to $D^4R^4$, so this interaction vanishes in the decompactification limit; the next term, $D^6R^4$, does not organize modularly and is left unresolved.
Load-bearing premise
The load-bearing premise is that the type IIA and type IIB four-graviton amplitudes are equal through two loops; the paper argues this by counting supermoduli contractions rather than by a completed string calculation, and that equality fixes the one-loop counterterm and forces the two-loop constant to cancel the leading divergence.
Editorial extensions
If this is right
- Eq. (5.1) gives a definite coefficient for the $s^2R^4$ term at two loops in type IIA and type IIB string theory, which a direct two-loop string calculation can check.
- The Eisenstein series $E_{5/2}$ predicts an infinite set of D-instanton corrections to $D^4R^4$ with fixed coefficients.
- The $D^4R^4$ interaction is absent in the decompactified eleven-dimensional limit because the leading two-loop divergence is cancelled by the two-loop counterterm.
- The $D^6R^4$ term is not captured by the same modular organization, which suggests that higher-loop supergravity effects contribute there.
Reading between the lines
- If the predicted two-loop string coefficient is confirmed, it would show that a calculation in a non-renormalizable eleven-dimensional theory can capture a genuine two-loop string effect once the ultraviolet sensitivity is handled by duality.
- The same auxiliary-torus method could be applied to other protected higher-derivative couplings; the failure of $D^6R^4$ to fit the modular scheme makes it the natural next test case.
- The equality of type IIA and type IIB amplitudes through two loops, if it survives higher-loop scrutiny, would suggest a non-renormalization pattern constraining which superspace integrals can contribute to these couplings.
- A mismatch in the D-instanton coefficients would indicate that the eleven-dimensional supergravity calculation is missing non-perturbative states that the full M-theory supplies.
Original abstract
The two-loop Feynman diagram contribution to the four-graviton amplitude of eleven-dimensional supergravity compactified on a two-torus, T^2, is analyzed in detail. The Schwinger parameter integrations are re-expressed as integration over the moduli space of a second torus, \hat T^2, which enables the leading low-momentum contribution to be evaluated in terms of maps of \hat T^2 into T^2. The ultraviolet divergences associated with boundaries of moduli space are regularized in a manner that is consistent with the expected duality symmetries of string theory. This leads to an exact expression for terms of order D^4 R^4 in the effective M theory action (where R^4 denotes a contraction of four Weyl tensors), thereby extending earlier results for the R^4 term that were based on the one-loop eleven-dimensional amplitude. Precise agreement is found with terms in type IIA and IIB superstring theory that arise from the low energy expansion of the tree-level and one-loop string amplitudes and predictions are made for the coefficients of certain two-loop string theory terms as well as for an infinite set of D-instanton contributions. The contribution at the next order in the derivative expansion, D^6 R^4, is problematic, which may indicate that it mixes with higher-loop effects in eleven-dimensional supergravity.
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
The two-loop Feynman diagram contribution to the four-graviton amplitude of eleven-dimensional supergravity compactified on a two-torus, T^2, is analyzed in detail. The Schwinger parameter integrations are re-expressed as integration over the moduli space of a second torus, \hat T^2, which enables the leading low-momentum contribution to be evaluated in terms of maps of \hat T^2 into T^2. The ultraviolet divergences associated with boundaries of moduli space are regularized in a manner that is consistent with the expected duality symmetries of string theory. This leads to an exact expression for terms of order D^4 R^4 in the effective M theory action (where R^4 denotes a contraction of four Weyl tensors), thereby extending earlier results for the R^4 term that were based on the one-loop eleven-dimensional amplitude. Precise agreement is found with terms in type IIA and IIB superstring theory that arise from the low energy expansion of the tree-level and one-loop string amplitudes and predictions are made for the coefficients of certain two-loop string theory terms as well as for an infinite set of D-instanton contributions. The contribution at the next order in the derivative expansion, D^6 R^4, is problematic, which may indicate that it mixes with higher-loop effects in eleven-dimensional supergravity.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | The two-loop Feynman diagram contribution to the four-graviton amplitude of eleven-dimensional supergravity compactified on a two-torus, T^2, is analyzed in detail. | contribution 0.99 | 0.90 | 0.05 | asserted 0.98 |
| s1 | The Schwinger parameter integrations are re-expressed as integration over the moduli space of a second torus, \hat T^2, which enables the leading low-momentum contribution to be evaluated in terms of maps of \hat T^2 into T^2. | method 0.98 | 0.92 | 0.06 | asserted 1.00 |
| s2 | The ultraviolet divergences associated with boundaries of moduli space are regularized in a manner that is consistent with the expected duality symmetries of string theory. | method 0.98 | 0.89 | 0.04 | asserted 0.89 |
| s3 | This leads to an exact expression for terms of order D^4 R^4 in the effective M theory action (where R^4 denotes a contraction of four Weyl tensors), thereby extending earlier results for the R^4 term that were based on the one-loop eleven-dimensional amplitude. | result 0.98 | 0.93 | 0.49 | asserted 1.00 |
| s4 | Precise agreement is found with terms in type IIA and IIB superstring theory that arise from the low energy expansion of the tree-level and one-loop string amplitudes and predictions are made for the coefficients of certain two-loop string theory terms as well as for an infinite set of D-instanton contributions. | result 0.98 | 0.92 | 0.33 | asserted 1.00 |
| s5 | The contribution at the next order in the derivative expansion, D^6 R^4, is problematic, which may indicate that it mixes with higher-loop effects in eleven-dimensional supergravity. | limitation 0.95 | 0.82 | 0.05 | hedged possibility 0.93 |
What was examined, and what was not
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Figures
Figures reproduced from arXiv:hep-th/9910055 by the authors.
References
How later papers used it
78 later papers cite it
3 later papers by other authors are listed below: 2 used its method or tool and 1 used its data or values. 1 more paper by the same authors is listed: 1 used its method or tool.
Uses its method or tool 3 of 10 papers with this label · 1 by the same authors
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Followed this paper's approach in using the results in another work to analyze the SL(2,Z)-invariant theta integral.
Some finite terms from ladder diagrams in three and four loop maximal supergravity (2015) · 0.99 · paraphrased: the licence does not allow quoting
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Isolated the boundary contribution along the lines of this paper and mentioned only the results.
The D^6 R^4 term from three loop maximal supergravity (2014) · 0.99 · paraphrased: the licence does not allow quoting
By the same authors
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Used this paper's method of orbits to split the integral into three kinds of pieces.
Automorphic properties of low energy string amplitudes in various dimensions (2010) (same authors) · 0.99 · paraphrased: the licence does not allow quoting
Uses its data or values 1 of 5 papers with this label
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Fixed its overall normalization using the answer from this paper's two-loop supergravity.
Perturbative type II amplitudes for BPS interactions (2015) · 0.87 · paraphrased: the licence does not allow quoting
How the literature uses it
72 arXiv papers cite this in 196 sentences
Papers citing it · 129 sentences without a confident label
Builds on it 1 paper
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The method used to evaluate these integrals is an extension of that used for the $(0,1)$ case in [ref] , which we will review in the appendix [ref] ($I_(1,0)^(d=10)$ was evaluated in [ref] ).
Modular properties of two-loop maximal supergravity and connections with string theory · Interactions from circle compactification to ten dimensions · 0.92
Uses its method or tool 10 papers
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To evaluate eval, we further define [ref] τ_1 = ρ̂/ρ̂+λ̂, τ_2 = √(Δ̂_2(,ł̂,̊̂))/ρ̂+λ̂, V_2 = l_11^2 √(Δ̂_2(,ł̂,̊̂)),to get that 𝒜_D^4ℛ^4^(2) = π^11κ_11^4/(2π)^D l_11^8 _2ℛ^4∑_m̂^I, n̂^I∫_0^∞dV_2 V_2^3 ∫_ℱ_2 d^2 τ/τ_2^2 e^-π^2 G_IJ (m̂+n̂τ)^I (m̂+n̂τ̅)^J V_2/τ_2,where $d^2 τ= dτ_1 dτ_2$ and $ℱ_2$ is the fundamental domain of $SL(2,ℤ)$ defined by ℱ_2 = { -1/2 ≤τ_1 ≤1/2, τ_2 ≥0, |τ|^2 ≥1}.Thus $V_2$ and $τ$ parametrize the volume and complex structure of an auxiliary $T^2$.
Non--analytic terms from nested divergences in maximal supergravity · The $ℛ^4$, $D^2ℛ^4$ and $D^4ℛ^4$ coefficient functions from supergravity amplitudes · 0.91
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The integral over $τ$ in the $(m̂,n̂) (0,0)$ piece can be `unfolded' to the infinite strip as in [ref] , giving h_(p,q)^0 (1) = π^5 b_(p,q)^0 ∫_chi^dVV ( ∫_d^2ττ_2^2 +∫_0^∞dtt^2∑_p≠0exp(-πp^2 v V/τ_2)) = π^6 b_(p,q)^03 ∫_chi^dVV + π^6 b_(p,q)^03v ∫_chi^dVV^2 .
Modular properties of two-loop maximal supergravity and connections with string theory · $h_(3,0)^0$, $h_(0,2)^0$ · 0.96
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Hence we only need to isolate the boundary contribution, which is done along the lines of [ref] and so we only mention the results.
The D^6 R^4 term from three loop maximal supergravity · The two loop four graviton amplitude · 0.99
Uses its data or values 5 papers
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Using the ten dimensional values $λ^(10)_(0,0)=3/4$, $λ^(10)_(1,0)=15/4$ and $λ^(10)_(0,1)=12$ determined in [ref] , we deduce that the coefficients of the terms discussed in [ref] satisfy the following set of Laplace eigenvalue equations with source terms, [equation]
String theory dualities and supergravity divergences · Constraints on the coefficients · 0.99
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The contribution to the coefficient of the $σ_2 ^4∼^4 ^4$ term was shown in [ref] to have the form I^(d=10)_(1,0) + I_▹ (1,0)^(d=10) + δ_2 I^(d=10)_(1,0) = ζ(5)4 R_11^5 ,
Modular properties of two-loop maximal supergravity and connections with string theory · $(p,q)=(1,0)$ · 0.81
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For the $D^4ℛ^4$ interaction, from 1loop2 we get that ( λ^2 ^2/λ^2 +2 λ/λ-2)Î^(1)_D^4ℛ^4 =0,leading to I^(1)_D^4 ℛ^4 = 4/π^2ζ(3)ζ(4)(r^3 +1/r^3 ), where we have fixed the overall normalization using the answer from two loop supergravity [ref] .
Perturbative type II amplitudes for BPS interactions · The genus one amplitudes · 0.87
Compares with it 6 papers
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The various contributions in [ref] agree with the expressions obtained by evaluating the sum of one-loop and two-loop Feynman diagram contributions to the amplitude in eleven-dimensional supergravity compactified on a $(d+1)$-torus [ref] .
Eisenstein series for higher-rank groups and string theory amplitudes · Solutions for the coefficients $^(D)_(0,0)$ and $^(D)_(1,0)$. · 0.98
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In the absence of concrete answers at three and four loops, we consider in detail the analysis at two loops, where several amplitudes are known [ref] and we can use the results to compare with what we get based on our analysis in the main text.
Some finite terms from ladder diagrams in three and four loop maximal supergravity · Generalities and our analysis of the two loop amplitude · 0.91
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These coefficients follow from the methods described in appendix [ref], and the results agree with the type IIA expressions derived by taking the one-loop amplitude of eleven dimensional supergravity on $T^2$ [ref] .
Low energy expansion of the four-particle genus-one amplitude in type II superstring theory · Summary of the expansion of the nine-dimensional genus-one amplitude · 1.00
Cites it as background 26 papers
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Many D-instanton induced terms were predicted using S-duality invariances of various compactified string theories [ref] , but except for the early attempts [ref] , the direct systematic computation of these amplitudes from first principles has not been carried out.
Normalization of Type IIB D-instanton Amplitudes · Introduction · 0.97
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The terms in the low momentum expansion of the two loop four graviton amplitude up to the $D^12ℛ^4$ term have been obtained in [ref] .
Supergravity limit of genus two modular graph functions in the worldline formalism · Introduction · 0.90
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We review various details of the four graviton amplitude in $N=1$ supergravity in 11 dimensions compactified on $ℝ^8,1 ×T^2$ at one and two loops [ref] .
The D^6 R^4 term from three loop maximal supergravity · The four graviton supergravity amplitude at one and two loops · 0.91
Discussion
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