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REVIEW 2 major objections 4 minor 34 references

D-branes and nonlinear interactions in the $AdS$ pure spinor string

T0 review · 2 major / 4 minor · reviewed 2026-08-01 · deepseek-v4-flash

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Pith's one-line read Zero-field half-BPS D-brane boundary conditions in AdS5×S5 are claimed to reduce to involutions R of psu(2,2|4) with RΣR^{-1}=Σ^{-1}; boundary BRST invariance then gives a DBI-like system.

desk verdict Solid zero-field D-brane classification with a clear coordinate-independent construction, but the interacting boundary BRST system leans on an unproved non-degeneracy assumption in Eq. (5.44); the right verdict is conditional, not accept. read the letter →

arxiv 2607.26343 v1 pith:6K5A7OFJ submitted 2026-07-28 hep-th

Brenno Carlini Vallilo This is my paper · ORCID
classification hep-th PACS 11.25.-w11.30.Pb
keywords purespinorstringAdS5×S5D-braneshalf-BPSboundaryconditionsinvolutiveautomorphismsZ4gradingDirac-Born-InfeldequationsBRSTcurrent
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper develops a coordinate-independent, algebraic description of D-brane boundary conditions for the pure spinor string on AdS5×S5, in the closed-string channel. Its central proposal is that Lorentzian half-BPS D-branes with vanishing background flux correspond to involutive automorphisms R of the superalgebra psu(2,2|4) that exchange the two odd sectors of the Z4 grading; the fixed subalgebra of R selects the preserved symmetry and the Neumann directions. Seven such involutions are constructed, realizing the zero-flux D1, D3, D5, and D7 probe sectors that are the natural world-sheet analogues of known half-BPS supergravity probe geometries. The paper then builds a local ansatz for matter and ghost boundary interactions and derives the constraints imposed by the boundary BRST current: a coupled system (5.42)–(5.44) relating the tangential superconnection, the transverse embedding, and four ghost-gluing couplings, of Dirac-Born-Infeld type on the brane world-volume. A sympathetic reader should care because this replaces coordinate-dependent coset parametrizations with invariant structure and gives a local supercoset formulation of the boundary-BRST constraints for fluctuations about these branes.

What carries the argument

The load-bearing object is the involutive automorphism R of psu(2,2|4), subject to RΣR^{-1}=Σ^{-1}, where Σ generates the Z4 grading of the coset sigma model. This condition forces R to exchange the grade-1 and grade-3 sectors and to split the even sectors into fixed (Neumann) and anti-fixed (Dirichlet) parts; the fixed subalgebra yields the preserved half-BPS symmetry and the preserved world-volume. For the interacting problem, the machinery is the Cartan map C_R(g)=g^{-1}R(g), whose logarithmic branch defines the transverse coordinate Y◦, and the exact graph differential Γ_Φ for the fluctuating brane g=g•e^{Φ◦}; its fixed and anti-fixed coset blocks T_Φ and N_Φ assemble into the nonlinear

What would settle it

Compute, for one of the seven probes, whether the antighost-quotient pairing restricted to the allowed boundary pure-spinor cone is non-degenerate; if a degenerate direction exists, the separation of (5.44) into two equations is unjustified. Alternatively, attempt to construct explicit ghost couplings M_{rs}(A•,Φ◦) for the AdS2 D1 that satisfy (5.42)–(5.44) on the cone; the absence of any non-zero solution would falsify the claim that these equations are the correct necessary consistency conditions.

Watch

Extended reading notes

Core claim

On the paper's own terms: zero-field boundary conditions for the AdS5×S5 pure spinor string are organized by involutive automorphisms R of psu(2,2|4) with RΣR^{-1}=Σ^{-1}, which preserve even grades, swap odd grades 1 and 3, and split directions into Neumann and Dirichlet parts. Seven representatives realize the zero-flux D1, D3, D5, D7 probe sectors. For interactions, with the brane the graph g=g•e^{Φ◦}, the embedding operator D_Φ, curvature F_Φ, and four ghost couplings M_{rs} obey M^{◦}(λ•+,λ◦−)+D_Φ(λ•+)=0 and M^{•}(λ•+,λ◦−)=ι_{λ•+}F_Φ+D†_Φ(λ◦−), plus antighost-quotient conditions: necessary local equations, all-order in the embedding, quadratic in ghosts, reducing at leading order to fla

Load-bearing premise

The derivation of the two antighost equations (5.44) assumes that the pairing on the antighost gauge quotient is non-degenerate on a smooth local patch of the pure-spinor cone; if that pairing is degenerate, the fixed and anti-fixed components need not vanish separately and the system (5.42)–(5.44) would not be the right consistency conditions.

Editorial extensions

If this is right

  • The AdS5×S5 half-BPS zero-flux D1, D3, D5, and D7 probe sectors are realized by seven explicit involutions; any unitary row with a (3,1) split of a defining four-space is ruled out by the condition RΣR^{-1}=Σ^{-1}.
  • The boundary BRST current, not the beta function, determines the world-volume dynamics of the brane matter and ghost couplings; the resulting equations are necessary consistency conditions on the allowed pure-spinor data.
  • At zero fields the interacting equations reduce to the fixed gluing condition ¯λ=R(λ), so the algebraic classification of boundary conditions is the free-field limit of the interacting system.
  • The transverse embedding Φ◦ determines the anti-fixed combination of ghost couplings, while the pulled-back Abelian curvature F_Φ determines the fixed combination; both are invariant under the open-string Abelian gauge symmetry.
  • The leading terms of the interacting equations reproduce the flat-space supersymmetric Born-Infeld boundary structure, so the curved background modifies rather than replaces that structure.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A testable extension: solve (5.42)–(5.44) explicitly for one probe, e.g. the AdS2 D1, to see whether the four ghost couplings admit non-zero solutions that preserve the pure-spinor cone; the paper leaves this unsolved.
  • The (3,1)-split obstruction suggests a general selection rule: for any Z4-graded supercoset, a boundary involution with eigenspaces of odd dimension cannot satisfy the grade-exchange condition, so the allowed fixed subalgebras are constrained by elementary linear algebra over the defining representation.
  • The paper restricts to field-independent involutions and zero flux; if the same method were extended to flux-deformed gluing, one would expect additional branches of boundary conditions, but the present classification would not cover them.
  • If the antighost-quotient pairing is degenerate on the pure-spinor cone, the split of equation (5.44) into two independent equations would fail, and the interacting system would be underdetermined for some probes; testing this degeneracy is a direct way to probe the robustness of the result.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 4 minor

Summary. The paper develops a coordinate-independent algebraic framework for zero-field boundary conditions in the AdS5×S5 pure spinor string. It organizes the boundary problem around an involutive automorphism R of psu(2,2|4) satisfying RΣR^{-1}=Σ^{-1}, uses the fixed/anti-fixed decomposition to identify Neumann and Dirichlet sectors, and constructs explicit matrix representatives for seven involutions (four inner, three outer) that are claimed to realize the Lorentzian zero-flux D1, D3, D5, and D7 probe sectors. The second main result is a local boundary action with matter and ghost interactions, from which the paper derives the interacting boundary-BRST consistency system (5.42)–(5.44) coupling the tangential superconnection, the transverse embedding, and four ghost-gluing couplings M_rs.

Significance. If the zero-field classification and the interacting consistency equations hold, this is a useful coordinate-independent contribution to D-brane boundary conditions in the AdS pure spinor string. The paper gives explicit matrix representatives, checks real forms and Z4 compatibility, and carefully distinguishes the external classification [26] as a necessary cross-check rather than as a circular input. It also states its own limitations honestly: grade preservation, pure-spinor-cone compatibility, and antighost-gauge compatibility of the four couplings are left as unsolved restrictions. The main weakness is that the derivation of (5.44) relies on an unproved non-degeneracy assumption, so the interacting part is conditional as written.

major comments (2)
  1. [§5.3, Eq. (5.44)] The step from the antighost term in Eq. (5.41) to the two equations (5.44a,b) requires that the pairing on the antighost gauge quotient be non-degenerate separately on each R-parity block, over the allowed pure-spinor data. The text merely asserts this on 'a smooth local patch'; no proof is given. This is stronger than ordinary non-degeneracy of the unreduced pairing, because the supertrace blocks decouple for R-invariant R-parity, and it must hold on the pure-spinor cone, which is not a smooth manifold. Since (5.44a,b) are part of the central consistency system, this unproved assumption is load-bearing. Please either prove the required non-degeneracy on the relevant strata or explicitly state that (5.44) is only derived modulo this assumption and characterize the resulting limitation.
  2. [§4.1, Table (4.11)] The D3 rows of the table list the fixed algebras as psu(1,1|2)⊕psu(1,1|2)⊕u(1) and psu(2|2)⊕psu(2|2)⊕R, while Section 3.3 lists the corresponding classification rows with two Abelian directions, u(1)^2 and R^2. Immediately below the table, Eqs. (4.12)–(4.13) introduce two independent Abelian block generators zAdS and zS and state that the Z4 grading places 'one Abelian direction in g•0 and the other in g•2.' As written, the table undercounts the Abelian factors in the D3 fixed algebras. This is central to the claim that the seven representatives realize the stated D3 sectors, so the labels and dimensions should be reconciled, or the quotient by the central identity should be explained explicitly.
minor comments (4)
  1. [Abstract / §5.3] The abstract calls (5.42)–(5.44) a 'set of Dirac-Born-Infeld-like equations of motion,' but the paper's own conclusion describes them as necessary local consistency conditions, with the actual solution of the projected superspace equations left to future work. The stronger phrasing is likely to mislead; I suggest 'necessary consistency equations of DBI type.'
  2. [§5.1, Eq. (5.6)] The notation m s¯1 is typeset ambiguously; writing m^s_{ar1} or defining the bar explicitly would improve readability.
  3. [§3.3] The paper says the absence of a D9 fixed algebra is a 'symmetry cross-check rather than a separate charge-state argument.' This is appropriately cautious, but the same caution should be applied to the statement that the seven representatives 'realize' all sectors: the table in §4.1 needs the correction noted above before this claim is fully supported.
  4. [Appendix B.1] The sentence 'For existence, no row-by-row fermionic calculation is needed' is helpful, but a short explicit illustration of the fermionic image of one representative would make the construction more transparent to readers not familiar with the matrix conventions.

Circularity Check

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No circularity found: the interacting equations are derived from boundary BRST invariance and stationarity, while imported algebra data are used only as consistency checks.

full rationale

The paper's central new result, Eqs. (5.42)-(5.44), is obtained by substituting the stationarity conditions (5.33) into the unreduced BRST flux (3.18)/(5.37); the four ghost-gluing couplings M_rs are introduced as arbitrary linear maps in the ansatz (5.8) and are then constrained by requiring the boundary BRST current to vanish. This is a derivation, not a fit of input to output. The candidate half-BPS algebra list is explicitly imported from the external classification [26] and used as a necessary symmetry test, with the paper stating that the converse implication is absent; Section 4 then verifies representatives against Eq. (B.32), so the geometry section is a compatibility check rather than a prediction. The self-citations (e.g. [4,5,7,16,29,31]) are for conventions and prior formalism and are not load-bearing for the new equations. The paper also defines its 'D-brane' scope as involutive-gluing zero-field configurations, so the claim that involutions organize the construction is a framework, not a derived universal. The only identified soft spot is Section 5.3's 'On a smooth local patch, non-degeneracy of the quotient pairing therefore requires both components of the covariant variation to vanish' -- an unproved technical assumption and a correctness risk, but not circular: it does not reduce Eq. (5.44) to its own input, nor is it supported by a self-citation chain.

Assumptions & free parameters 0 free parameters · 6 assumptions · 0 invented entities

The central construction rests on the listed domain assumptions plus the external half-BPS algebra list of [26]. No numerical free parameters are fitted to data. No new physical entities are introduced; the four ghost-gluing couplings are auxiliary boundary maps, not new particles or forces. The interacting equations additionally rely on an unproved non-degeneracy assumption on the antighost quotient pairing.

assumptions (6)
  • standard math The psu(2,2|4) superalgebra, its Z4 grading, supertrace orthogonality, and the real forms osp(4*|4) and osp(4|4;R) are as reviewed in Appendices A and B.
    Used throughout; conventions taken from Ref. [26] and the author's prior formalism [7,29].
  • domain assumption The pure spinor action, BRST transformations, and on-shell nilpotence modulo local H0 and pure-spinor gauge symmetry are those of Berkovits/Vallilo (Eqs. (3.1), (3.7)).
    Section 3; the boundary BRST derivation starts from this action and these transformations.
  • domain assumption A compatible boundary involution must be a complex-linear automorphism preserving bracket, supertrace, real form, and local grade-zero algebra, and satisfying RΣR^{-1}=Σ^{-1}; antilinear maps are excluded.
    Sections 3.1 and 4, Eq. (4.1); this restricts the claimed framework to field-independent complex-linear zero-flux cases.
  • domain assumption The local factorization g = g• e^{Y◦} with Y◦ = -1/2 Log_U C_R(g) exists and all fluctuations stay in the chosen logarithmic branch.
    Section 3.2, Eqs. (3.46)-(3.51); the position coupling and graph ansatz depend on this branch.
  • ad hoc to paper The field-dependent gluing is generated by the quadratic ghost interaction (5.8) with four unknown couplings M_rs; the allowed pure-spinor domain is inherited from the zero-field gluing.
    Section 5.1; the authors state this ansatz is assumed and that the restrictions on the couplings are not solved.
  • ad hoc to paper The antighost gauge quotient pairing is non-degenerate, so Eq. (5.44) forces both R-parity components of the covariant variation to vanish.
    Section 5.3; no proof is supplied for non-degeneracy on the allowed pure-spinor cone.

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Pith. "Pith review of D-branes and nonlinear interactions in the $AdS$ pure spinor string." pith.science (2026). https://pith.science/paper/6K5A7OFJ

@misc{pith2026260726343,
  author       = {Pith},
  title        = {Pith review of: D-branes and nonlinear interactions in the $AdS$ pure spinor string},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/6K5A7OFJ}},
  note         = {Machine review of arXiv:2607.26343}
}
abstract

We develop a coordinate-independent algebraic description of zero-field boundary conditions for the pure spinor string on $AdS_5\times S^5$ in the closed-string channel. The construction is organized by involutive automorphisms of $\mathfrak{psu}(2,2|4)$ that exchange the odd sectors of the $\mathbb Z_4$ grading. Their fixed subalgebras provide candidate half-BPS, Lorentzian D-brane geometries with vanishing background world-volume flux, consistent with the standard $AdS_2$, $AdS_3\times S^1$, $AdS_4\times S^2$, and related embeddings. Together, the seven representatives realize the Lorentzian zero-flux D1, D3, D5, and D7 probe sectors considered here. We then construct a local ansatz for the matter and ghost boundary interactions and derive a system of consistency equations for the tangential superconnection, transverse embedding, and four ghost-gluing couplings. The resulting system is a set of Dirac-Born-Infeld-like equations of motion on the brane world-volume.

Figures

Figures reproduced from arXiv: 2607.26343 by the authors.

Figure 1
Figure 1. Local geometry of the nonlinear embedding operator. The drawing is schematic: fixed and [PITH_FULL_IMAGE:figures/full_fig_p026_1.png] view at source ↗

Discussion (0). Continue with ORCID to comment.

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Works this paper leans on

34 extracted references · 34 linked inside Pith

  1. [24]

    Hanazawa and M

    S. Hanazawa and M. Sakaguchi,D-branes from pure spinor superstring in AdS5× S5 background, Nucl. Phys.B914(2017) 234–247,arXiv:1609.05457 [hep-th]. 38

    arXiv 2017

  2. [26]

    D’Hoker, J

    E. D’Hoker, J. Estes, M. Gutperle, D. Krym, and P. Sorba,Half-BPS supergravity solutions and superalgebras, JHEP12(2008) 047,arXiv:0810.1484 [hep-th]

    arXiv 2008

  3. [1]

    Berkovits,Super Poincare covariant quantization of the superstring, JHEP04(2000) 018, arXiv:hep-th/0001035 [hep-th]

    N. Berkovits,Super Poincare covariant quantization of the superstring, JHEP04(2000) 018, arXiv:hep-th/0001035 [hep-th]

    arXiv 2000

  4. [2]

    Gomez and C

    H. Gomez and C. R. Mafra,The closed-string 3-loop amplitude and S-duality, JHEP10(2013) 217,arXiv:1308.6567 [hep-th]

    arXiv 2013

  5. [3]

    Berkovits and O

    N. Berkovits and O. Chandia,Superstring vertex operators in anAdS5 ×S 5 background, Nucl. Phys.B596(2001) 185–196,arXiv:hep-th/0009168 [hep-th]

    arXiv 2001

  6. [4]

    B. C. Vallilo,One loop conformal invariance of the superstring in anAdS5 ×S 5 background, JHEP12(2002) 042,arXiv:hep-th/0210064 [hep-th]

    arXiv 2002

  7. [5]

    B. C. Vallilo,Flat currents in the classicalAdS5 ×S 5 pure spinor superstring, JHEP03(2004) 037,arXiv:hep-th/0307018 [hep-th]

    arXiv 2004

  8. [6]

    Berkovits,BRST cohomology and nonlocal conserved charges, JHEP02(2005) 060, arXiv:hep-th/0409159 [hep-th]

    N. Berkovits,BRST cohomology and nonlocal conserved charges, JHEP02(2005) 060, arXiv:hep-th/0409159 [hep-th]

    arXiv 2005

Show all 34 references
  1. [7]

    Chandia, W

    O. Chandia, W. D. Linch, and B. C. Vallilo,Master symmetry in the AdS5×S 5 pure spinor string, JHEP01(2017) 024,arXiv:1607.00391 [hep-th]

    2017 arXiv

  2. [8]

    Berkovits and R

    N. Berkovits and R. S. Pitombo,4D Chern–Simons and the pure spinorAdS5 ×S 5 superstring, arXiv:2401.03976 [hep-th]. 37

    arXiv

  3. [9]

    Berkovits,Quantum consistency of the superstring inAdS5 ×S 5 background, JHEP03 (2005) 041,arXiv:hep-th/0411170 [hep-th]

    N. Berkovits,Quantum consistency of the superstring inAdS5 ×S 5 background, JHEP03 (2005) 041,arXiv:hep-th/0411170 [hep-th]

    2005 arXiv

  4. [10]

    Mazzucato and B

    L. Mazzucato and B. C. Vallilo,On the Non-renormalization of the AdS Radius, JHEP09 (2009) 056,arXiv:0906.4572 [hep-th]

    2009 arXiv

  5. [11]

    O. A. Bedoya, D. Z. Marchioro, D. L. Nedel, and B. Carlini Vallilo,Quantum Current Algebra for theAdS 5 ×S 5 Superstring, JHEP08(2010) 026,arXiv:1003.0701 [hep-th]

    2010 arXiv

  6. [12]

    B. C. Vallilo and L. Mazzucato,The Konishi multiplet at strong coupling, JHEP12(2011) 029, arXiv:1102.1219 [hep-th]

    2011 arXiv

  7. [13]

    Ramirez and B

    I. Ramirez and B. C. Vallilo,Worldsheet dilatation operator for theAdS superstring, JHEP05 (2016) 129,arXiv:1509.00769 [hep-th]

    2016 arXiv

  8. [14]

    O. A. Bedoya, L. I. Bevilaqua, A. Mikhailov, and V. O. Rivelles,Notes on beta-deformations of the pure spinor superstring inAdS5 ×S 5, Nucl. Phys.B848(2011) 155–215, arXiv:1005.0049 [hep-th]

    2011 arXiv

  9. [15]

    Berkovits and T

    N. Berkovits and T. Fleury,Harmonic Superspace from theAdS5 ×S 5 Pure Spinor Formalism, JHEP03(2013) 022,arXiv:1212.3296 [hep-th]

    2013 arXiv

  10. [16]

    Chandia and B

    O. Chandia and B. C. Vallilo,A superfield realization of the integrated vertex operator in an AdS5 ×S 5 background, JHEP10(2017) 178,arXiv:1709.05517 [hep-th]

    2017 arXiv

  11. [17]

    Fleury and L

    T. Fleury and L. N. S. Martins,AdS5 ×S 5 supergravity vertex operators, JHEP07(2021) 210, arXiv:2104.03333 [hep-th]

    2021 arXiv

  12. [18]

    Berkovits and V

    N. Berkovits and V. Pershin,Supersymmetric Born-Infeld from the pure spinor formalism of the open superstring, JHEP01(2003) 023,arXiv:hep-th/0205154 [hep-th]

    2003 arXiv

  13. [19]

    Hanazawa and M

    S. Hanazawa and M. Sakaguchi,Supersymmetric DBI equations in diverse dimensions from the BRS invariance of a pure spinor superstring, Phys. Rev. D100(2019) 046006, arXiv:1904.12330 [hep-th]

    2019 arXiv

  14. [20]

    Fujii, S

    R. Fujii, S. Hanazawa, H. Kanehisa, and M. Sakaguchi,Supersymmetric non-Abelian DBI equations from an open pure spinor superstring, Phys. Rev. D108(2023) 046002, arXiv:2304.04899 [hep-th]

    2023 arXiv

  15. [21]

    Anguelova and P

    L. Anguelova and P. A. Grassi,Super D-branes from BRST symmetry, JHEP11(2003) 010, arXiv:hep-th/0307260 [hep-th]

    2003 arXiv

  16. [22]

    Schiappa and N

    R. Schiappa and N. Wyllard,D-brane boundary states in the pure spinor superstring, JHEP07 (2005) 070,arXiv:hep-th/0503123 [hep-th]

    2005 arXiv

  17. [23]

    Mukhopadhyay,On D-brane boundary state analysis in pure-spinor formalism, JHEP03 (2006) 066,arXiv:hep-th/0505157 [hep-th]

    P. Mukhopadhyay,On D-brane boundary state analysis in pure-spinor formalism, JHEP03 (2006) 066,arXiv:hep-th/0505157 [hep-th]

    2006 arXiv

  18. [25]

    Sakaguchi and K

    M. Sakaguchi and K. Yoshida,D-branes of covariant AdS superstrings, Nucl. Phys.B684(2004) 100–124,arXiv:hep-th/0310228 [hep-th]

    2004 arXiv

  19. [27]

    Li,Boundary states of D-branes and Dy strings, Nucl

    M. Li,Boundary states of D-branes and Dy strings, Nucl. Phys.B460(1996) 351–361, arXiv:hep-th/9510161 [hep-th]

    1996 arXiv

  20. [28]

    C. G. Callan, Jr. and I. R. Klebanov,D-brane boundary state dynamics, Nucl. Phys.B465 (1996) 473–486,arXiv:hep-th/9511173 [hep-th]

    1996 arXiv

  21. [29]

    Ramirez and B

    I. Ramirez and B. C. Vallilo,Supertwistor description of theAdS pure spinor string, Phys. Rev. D93(2016) no. 8, 086008,arXiv:1510.08823 [hep-th]

    2016 arXiv

  22. [30]

    Berkovits and C

    N. Berkovits and C. Vafa,Towards a Worldsheet Derivation of the Maldacena Conjecture, JHEP 03(2008) 031,arXiv:0711.1799 [hep-th]. [AIP Conf. Proc.1031,21(2008)]

    2008 arXiv

  23. [31]

    Chandia and B

    O. Chandia and B. C. Vallilo,Non-minimal fields of the pure spinor string in general curved backgrounds, JHEP02(2015) 092,arXiv:1412.1030 [hep-th]

    2015 arXiv

  24. [32]

    A. Yu. Alekseev and V. Schomerus,D-branes in the WZW model, Phys. Rev.D60(1999) 061901,arXiv:hep-th/9812193 [hep-th]

    1999 arXiv

  25. [33]

    Stanciu,D-branes in anAdS 3 background, JHEP09(1999) 028,arXiv:hep-th/9901122 [hep-th]

    S. Stanciu,D-branes in anAdS 3 background, JHEP09(1999) 028,arXiv:hep-th/9901122 [hep-th]

    1999 arXiv

  26. [34]

    I. Bena, J. Polchinski, and R. Roiban,Hidden symmetries of theAdS5 ×S 5 superstring, Phys. Rev.D69(2004) 046002,arXiv:hep-th/0305116 [hep-th]. 39

    2004 arXiv

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