Asymmetric $\lambda$-deformed cosets

Bin Chen; Jia Tian; Jue Hou

REVIEW 1 major objections 6 minor 18 references

Asymmetric $\lambda$-deformed cosets

T0 review · 1 major / 6 minor · reviewed 2026-08-14 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read This paper claims that asymmetric $\lambda$-deformation of the cosets $SO(n+1)/SO(n)$ is not a new family: a $Z_2$ transformation $\theta_i \to \pi-\theta_i$, $\lambda \to -\lambda$ maps each asymmetric deformed geometry onto the standard…

desk verdict A solid paper proving a Z2 equivalence between asymmetric and symmetric λ-deformed SO(n+1)/SO(n) cosets, with useful recursion relations; the one real gap is the unverified vanishing of the B-field. read the letter →

arxiv 1908.10004 v2 pith:4R7NPN7A submitted 2019-08-27 hep-th

Jia Tian , Jue Hou , Bin Chen This is my paper · ORCID

classification hep-th

keywords asymmetricλ-deformationintegrablesigmamodelscosetSO(n+1)/SO(n)Z2dualitygaugedWZWdeformedtarget-spacegeometry

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

This paper studies whether the asymmetric $\lambda$-deformation prescription, which gauges the coset $SO(n+1)/SO(n)$ with an outer-automorphism twist instead of the identity, produces genuinely new integrable models. The authors construct the full deformed target-space geometries for arbitrary $n$ and establish a $Z_2$ equivalence: under $\theta_i \to \pi-\theta_i$ and $\lambda \to -\lambda$, every asymmetric geometry becomes the standard symmetric $\lambda$-deformed geometry. If correct, the asymmetric construction adds no new deformation parameter for this coset family, and all integrability and background properties follow from previously known symmetric results. This matters because integrable $\sigma$ models are scarce and the coset $SO(n+1)/SO(n)$ is the sphere $S^n$, which by analytic continuation is related to anti-de Sitter space, so the classification of deformed backgrounds has direct use for string-theory embeddings.

What carries the argument

The load-bearing object is the coset representative $g'_{n+1}=t'_1 t'_2 \cdots t'_n$, where each $t'_i$ is a rotation $e^{\sqrt{2}i\theta_i T_{n+1-i,n+2-i}}$ in $SO(n+1)$; this choice is independent of the automorphism $W$ and makes the Maurer-Cartan matrix $D^{AB}$ block-recursive. The deformed geometry is encoded in the frame $e^\alpha = L^\alpha - d_2^T (d_1 - W_a)^{-T} L^a$ and the matrix $P^{-T} = d_4 - d_3(d_1 - W_a)^{-1}d_2 - \lambda^{-1} W_\alpha$, with metric $ds^2 = \frac{k}{2\pi}\frac{1-\lambda^2}{\lambda^2} e^T P^T P e$ and dilaton $e^{-2\Phi} = e^{-2\Phi_0} \det(1 - W_a d_1)$ up to constants. The proof that the $Z_2$ map is an equivalence runs by induction on $n$, using recursion relations for $d_1$, $d_4$, and the quantity $Q = d_4 - d_3(d_1-1)^{-1}d_2$, which satisfies $Q^T Q = I$ and in fact $Q=J$; since $Q$ has eigenvalues $\pm1$, the dilaton determinant factors into trigonometric closed forms. These recursions also give a direct addition-and-multiplication construction of all deformed geometries for arbitrary $n$.

What would settle it

Explicitly compute the antisymmetric Kalb-Ramond component of the action (2.5) for the simplest nontrivial case, $SO(4)/SO(3)$, without invoking the vanishing argument, and check whether $B_{\mu\nu}$ stays zero or transforms as $B \to B$ under $\theta_i \to \pi-\theta_i$, $\lambda \to -\lambda$. A nonzero B-field, or a B-field that does not map to the symmetric model's B-field, would falsify the claimed identification of the full target-space backgrounds. Alternatively, compute the scalar one-loop spectrum for a higher representation and verify the exact $\lambda \to -\lambda$ map predicted by the geometry.

Watch

Extended reading notes

Core claim

The paper's central claim is that the asymmetric $\lambda$-deformation of the coset $SO(n+1)/SO(n)$ --- constructed by gauging with an outer-automorphism twist $W$ instead of the identity --- is not a genuinely new family of integrable models. For every $n \ge 2$, the target-space geometry of the asymmetric model can be transformed into the ordinary symmetric ($W=I$) $\lambda$-deformed geometry by the $Z_2$ map $\theta_i \to \pi - \theta_i$, $\lambda \to -\lambda$ (up to additional coordinate changes). The proof is inductive: a recursive coset representative $t'_i = e^{\sqrt{2}i\theta_i T_{n+1-i,n+2-i}}$ makes the frame one-forms, the matrix $P P^T$, and the dilaton each invariant under the combined coordinate and parameter reflection, so the whole metric is mapped onto the symmetric one. The paper also shows the transformation is physically meaningful: scalar spectra on the deformed geometry are not invariant under $\lambda \to -\lambda$, so the sign flip is not a relabeling but the precise statement of the equivalence.

Load-bearing premise

The argument that the full background is mapped correctly assumes that the Kalb-Ramond 2-form is identically zero; the paper states this follows from the same reasoning as in [14, 8] (footnote 2, Section 2), but the $Z_2$ invariance proof shown in Appendix B checks only the metric and the dilaton. If the B-field is nonzero, the equivalence of the two string backgrounds would need a separate verification.

Editorial extensions

If this is right

For every $n \ge 2$, the asymmetric $\lambda$-deformed $SO(n+1)/SO(n)$ geometries can be obtained from the symmetric ones by $\theta_i \to \pi-\theta_i$, $\lambda \to -\lambda$; hence the asymmetric models inherit exact integrability from the symmetric models.
The recursive formulas (3.38), (3.41), and (B.11) give the deformed metrics and dilatons for arbitrary $n$ using only matrix additions and multiplications, once the symmetric-frame variables are known.
For $SO(2n+1)/SO(2n)$, where the twisting automorphism is actually a gauge transformation, the scalar spectrum is invariant under $\lambda \to -\lambda$.
The scalar-field computation for $SO(4)/SO(3)$ shows that $\lambda \to -\lambda$ is not a coordinate relabeling: the spectrum changes under the sign flip, so the $Z_2$ map genuinely identifies two a priori different geometries.
The results put the asymmetric construction for these cosets into the same classification class as the symmetric one, so no new integrable deformation parameter is introduced by this asymmetry.

Reading between the lines

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

If the equivalence holds, every observable of the asymmetric model --- beta function, S-matrix, entanglement data --- can be computed in the symmetric frame with parameter $-\lambda$; this is an editorial inference because the paper stops at geometry and scalar spectra.
The same $Z_2$ idea might apply to other cosets with outer automorphisms, for example $SO(2n)/U(n)$, but the proof here depends on the specific block recursion, so any extension is a conjecture rather than a corollary.
A direct computation of the Kalb-Ramond field would settle whether the identification holds at the level of full supergravity backgrounds, not just the metric and dilaton; the vanishing assumption is the part most worth checking.
If the equivalence survives at the quantum level, the phrase 'asymmetric $\lambda$-deformation' for $SO(n+1)/SO(n)$ should be understood as a gauge or orientation choice rather than a new integrable sector.

Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

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

Desk Editor's Note

read the letter

Short version: this is a good, publishable paper. The main thing to know is that it proves a Z2 map between the asymmetric λ-deformed SO(n+1)/SO(n) models and the symmetric ones, with λ flipped to −λ, so the asymmetric family is not independent—it extends the symmetric family to negative λ. The induction proof is explicit, and the recursion relations in §3.5 give a genuinely useful way to build the deformed geometries for arbitrary n.

What's new: the Z2 equivalence (3.32) and the recursion relations (3.38), (3.41). The paper credits [1] for the asymmetric prescription and [6,7] for the symmetric geometries; it doesn't overclaim. The scalar spectrum check for SO(4)/SO(3) is a nice, honest demonstration that the parameter flip is physical and not just a coordinate relabeling.

The main soft spot is the Kalb-Ramond field. The metric and dilaton are checked in Appendix B, but the B-field is never computed. Footnote 2 simply says it vanishes by analogy with [14,8]. That is a genuine gap. The asymmetric gauge W≠I is exactly where the vector-gauge argument might fail, and if B is nonzero the full sigma-model equivalence under the Z2 transformation is not established. I think the claim is probably true—the known symmetric coset backgrounds do have B=0—but the authors should be asked to show it, not cite it. This is a moderate omission, not a fatal one.

A secondary issue: some steps in Appendix B are compressed. The induction is plausible but takes some effort to verify; a referee should check the base cases and the W-transformation conventions carefully.

Overall: the paper is a solid contribution to the integrable-deformation program. It deserves a serious referee and likely publication after a revision that addresses the B-field explicitly.

Referee Report

1 major / 6 minor

Summary. This paper studies integrable asymmetric λ-deformations of the coset models SO(n+1)/SO(n), following the gauge prescription of Driezen, Sevrin, and Thompson. The authors choose a recursive coset representative, compute the relevant automorphism W, and construct the target-space geometries in terms of frames e and a matrix P. The main result is that the asymmetric deformed geometries are mapped to the symmetric (W=I) λ-deformed geometries by the Z2 transformation (3.32): θ_i → π−θ_i, λ → −λ, up to some coordinate transformations. The metric and dilaton invariance under this map is proven in Appendix B, and recursion relations for the metric and dilaton data are given in Section 3.5. A scalar-spectrum check in the SO(4)/SO(3) example illustrates that the reflection of λ is physically non-trivial.

Significance. If the claimed equivalence holds for the full target-space background, it is a significant structural result: it shows that, for the SO(n+1)/SO(n) family, the asymmetric λ-deformation is not a new integrable model but a reparametrization of the symmetric one with a reflected deformation parameter. The paper provides explicit recursive constructions, a concrete induction proof, and a useful scalar-spectrum consistency test. The main caveat is that the proof covers the metric and dilaton, while the antisymmetric B-field is asserted to vanish by reference to earlier work; the completeness of the equivalence therefore rests on an imported assertion that is not verified in the asymmetric gauge.

major comments (1)

[§2, footnote 2; Appendix B] The central claim requires the full sigma-model background to be mapped by (3.32). The proof in Appendix B shows that the frames transform as e → −e, that PP^T is invariant, and that the dilaton is invariant, but it never computes or transforms the Kalb-Ramond field. Footnote 2 states that the B-field vanishes "for a similar argument given in [14,8]", but that argument is not reproduced, and the asymmetric gauge W≠I is precisely the case where a vector-gauge argument may fail. Please add an explicit computation of the antisymmetric two-form in the background, or a precise demonstration that the cited proof extends verbatim to the W of Eq. (3.31). Without this, the equivalence between the asymmetric and symmetric λ-deformed models is not fully established, since the action (2.5) contains the Wess-Zumino term.

minor comments (6)

[§2, footnote 2] The citation "[14,8]" is vague; please state exactly which result in those papers shows B=0 and why the same argument applies in the axial (W≠I) gauge.
[§3.3, "Scalar field" paragraph] The phrase "In this appendix" appears in the main text; this is presumably meant to be "In this subsection", or the scalar-field calculation should be moved to a formal appendix.
[§3.4, after Eq. (3.32)] The phrase "up to some other coordinate transformations" is imprecise; please spell out the additional coordinate transformations, such as the gauge-fixing reparametrizations used in the SO(4)/SO(3) example, so that the reader can reproduce the map explicitly.
[§3.5, Eq. (3.38)] The nested matrix notation in the recursion relation for Q is difficult to parse; introducing a short auxiliary vector would make the pattern more transparent.
[§3.5, Eq. (3.41)] The displayed result for (d1|n+1−1)−1d2|n+1 appears to contain mismatched square brackets; the typesetting should be checked.
[§3.3, scalar spectrum] The representation labels (L1,L2) are used without explaining their relation to the SO(4) quantum numbers; a brief comment would help the reader connect the calculation to [15].

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the Z2 equivalence is derived by induction from the external λ-deformation construction; the only gap is the uncomputed B-field, which is a rigor issue, not circularity.

full rationale

The paper's central claim is that the asymmetric λ-deformed SO(n+1)/SO(n) geometries are mapped to symmetric ones by θ_i → π−θ_i and λ → −λ. This is not obtained by fitting, by definitional recycling, or by the authors' own prior results. The deformed metric (2.10)–(2.11) follows from the gauged action (2.5) using the external prescription of [1], and the Z2 statement is then proved in Appendix B by direct computation: frames transform as e_α → −e_α, the combination P P^T is shown invariant using D D^T = 1 and W W^T = 1, and the dilaton reduces to det(1 − W_a d_1) which is invariant under the stated induction. No parameter is fitted and no quantity is renamed as a prediction. The scalar-field example in Section 3.3 uses the external Heun-equation method of [15] only as a diagnostic of the λ→−λ effect, not as an input to the equivalence proof. The only flagged weakness is footnote 2, where the Kalb-Ramond field is asserted to vanish 'for a similar argument given in [14,8]' rather than computed; if that assertion failed, the full target-space equivalence would be incomplete. However, this is a missing check based on an external cited argument, not a circular reduction of the paper's own derivation. There is no load-bearing self-citation chain, and no uniqueness theorem or ansatz is imported from the authors' own prior work. Accordingly, the derivation is self-contained apart from citing standard constructions, and the circularity score is 0.

Assumptions & free parameters 1 free parameters · 6 assumptions · 0 invented entities

The central claim rests on the external construction of asymmetric lambda-deformations [1], the known reduction of scalar fields to Heun's equation [15], and the standard coset representative of [18]. No new physical entities are introduced, and the only free parameter is the deformation parameter lambda, which is not fitted. The vanishing B-field assumption is the least independently verified ingredient.

free parameters (1)

lambda (deformation parameter)
The lambda-deformation parameter shared by all lambda-deformed models. It is an input of the model, not fitted to data; the Z2 map holds for every lambda in the range 0 < lambda < 1.

assumptions (6)

domain assumption The prescription of [1] for the asymmetric lambda-deformation, including the action (2.5) and the background metric (2.7), is correct.
Used throughout Sections 3 and 4 as the starting point; not re-derived in this paper.
domain assumption The Kalb-Ramond field vanishes for the deformed backgrounds.
Stated in footnote 2 of Section 2; the Z2 invariance proof checks only the metric and dilaton, so the full background would include B if this failed.
domain assumption The outer automorphism of so(2n) is given by W(T_ij) = -T_ij for j = 2n, else T_ij, as computed in Appendix A.
This W defines the axial gauge and is used in the geometry computation; the computation follows [16].
domain assumption The coset representative (3.8) is a valid global gauge fixing for SO(n+1)/SO(n).
Based on the decomposition of [18] and the gauge choices in Section 3.2.
domain assumption The scalar field equation on the lambda-deformed geometry reduces to the Heun equation (3.25) taken from [15].
Used in the scalar spectrum check of Section 3.3 to demonstrate that the Z2 parameter flip is physical.
standard math The block matrix inversion and determinant identities used in Appendices B and C are standard linear algebra.
Invoked without proof in the derivation of recursions.

how reviews work

0 comments

Cite this review

Pith. "Pith review of Asymmetric $\lambda$-deformed cosets." pith.science (2026). https://pith.science/paper/4R7NPN7A

@misc{pith2026190810004,
  author       = {Pith},
  title        = {Pith review of: Asymmetric $\lambda$-deformed cosets},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/4R7NPN7A}},
  note         = {Machine review of arXiv:1908.10004}
}

abstract

We study the integrable asymmetric $\lambda$-deformations of the $SO(n+1)/SO(n)$ coset models, following the prescription proposed in \cite{AsyLambda}. We construct all corresponding deformed geometries in an inductive way. Remarkably we find a $Z_2$ transformation which maps the asymmetric $\lambda$--deformed models to the symmetric $\lambda$--deformed models.

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

18 extracted references · 8 canonical work pages

[1]

Integrable asymmet ric λ-deformations,

S. Driezen, A. Sevrin and D. C. Thompson, “Integrable asymmet ric λ-deformations,” JHEP 1904, 094 (2019) [arXiv:1902.04142 [hep-th]]

arXiv 2019
[2]

Yang-Baxter sigma models and dS/AdS T duality,

C. Klimcik, “Yang-Baxter sigma models and dS/AdS T duality,” JHEP 0212, 051 (2002), hep-th/0210095; C. Klimcik, “On integrability of the Yang-Baxter sigma-model,” J. Math . Phys. 50, 043508 (2009), arXiv:0802.3518; C. Klimcik, “Integrability of the bi-Yang-Baxter sigma-model,” Lett. Math. Phys. 104, 1095 (2014), arXiv:1402.2105; C. Klimcik, “Poisson–Lie T...

arXiv 2002
[3]

An integrable deformation of the AdS5 x S5 su- perstring action,

F. Delduc, M. Magro and B. Vicedo, “An integrable deformation of the AdS5 x S5 su- perstring action,” Phys. Rev. Lett. 112, no. 5, 051601 (2014), [arXiv:1309.5850[hep- th]]; “Derivation of the action and symmetries of the q-deformed AdS5 × S5 superstring,” JHEP 1410, 132 (2014), [arXiv:1406.6286[hep-th]]

arXiv 2014
[4]

S-matrix for strings on η-deformed AdS5 x S5,

G. Arutyunov, R. Borsato and S. Frolov, “S-matrix for strings on η-deformed AdS5 x S5,” JHEP 1404, 002 (2014) [arXiv:1312.3542[hep-th]]; B. Hoare, R. Roiban and A. A. Tseytlin, “On deformations of AdSn x Sn super- cosets,” JHEP 1406, 002 (2014) [arXiv:1403.5517[hep-th]]; O. Lunin, R. Roiban and A. A. Tseytlin, “Supergravity backgrounds for defor- mations ...

arXiv 2014
[5]

Integrable interpolations: From exact CFTs to no n-Abelian T-duals,

K. Sfetsos, “Integrable interpolations: From exact CFTs to no n-Abelian T-duals,” Nucl. Phys. B 880, 225 (2014) [arXiv:1312.4560[hep-th]]

arXiv 2014
[6]

Integrab le Deformations of Strings on Symmetric Spaces,

T. J. Hollowood, J. L. Miramontes and D. M. Schmidtt, “Integrab le Deformations of Strings on Symmetric Spaces,” JHEP 1411, 009 (2014), [arXiv:1407.2840[hep-th]]; T. J. Hollowood, J. L. Miramontes and D. M. Schmidtt, “An Integrab le Defor- mation of the AdS5 × S5 Superstring,” J. Phys. A 47, no. 49, 495402 (2014) [arXiv:1409.1538[hep-th]]. K. Sfetsos and ...

arXiv 2014
[7]

Integrable λ-deformations: Squash- ing Coset CFTs and AdS5×S5,

S. Demulder, K. Sfetsos and D. C. Thompson, “Integrable λ-deformations: Squash- ing Coset CFTs and AdS5×S5,” JHEP 1507, 019 (2015), [arXiv:1504.02781[hep-th]]

arXiv 2015
[8]

Generalised integr able λ– and η- deformations and their relation,

K. Sfetsos, K. Siampos and D. C. Thompson, “Generalised integr able λ– and η- deformations and their relation,” Nucl. Phys. B 899, 489 (2015), [arXiv:1506.05784 [hep-th]]; Y. Chervonyi and O. Lunin, “Generalized λ-deformations of AdS p× Sp,” Nucl. Phys. B 913, 912 (2016), [arXiv:1608.06641 [hep-th]]; 22

arXiv 2015

Show all 18 references

[9]

Analytical structure of the generalized λ-deformation,

O. Lunin and W. Tian, “Analytical structure of the generalized λ-deformation,” Nucl. Phys. B 929, 330 (2018) [arXiv:1711.02735 [hep-th]]

2018 arXiv
[10]

A new class of integrable deforma tions of CFTs,

G. Georgiou and K. Sfetsos, “A new class of integrable deforma tions of CFTs,” JHEP 1703, 083 (2017) [arXiv:1612.05012 [hep-th]]; G. Georgiou and K. Sfetsos, “The most general λ-deformation of CFTs and integra- bility,” JHEP 1903, 094 (2019) [arXiv:1812.04033 [hep-th]]; G. Geo...

2017 arXiv
[11]

Nonabelian Bosonization in Two-Dimensions,

E. Witten, “Nonabelian Bosonization in Two-Dimensions,” Commun. Math. Phys. 92, 455 (1984)

1984
[12]

Interaction of Goldstone Particles in Two-Dime nsions. Applica- tions to Ferromagnets and Massive Yang-Mills Fields,

A. M. Polyakov, “Interaction of Goldstone Particles in Two-Dime nsions. Applica- tions to Ferromagnets and Massive Yang-Mills Fields,” Phys. Lett. 59B, 79 (1975)

1975
[13]

String propaga tion in a black hole geometry,

R. Dijkgraaf, H. L. Verlinde and E. P. Verlinde, “String propaga tion in a black hole geometry,” Nucl. Phys. B 371, 269 (1992); A. Giveon, “Target space duality and stringy black holes,” Mod. Phys . Lett. A 6, 2843 (1991); E. B. Kiritsis, “Duality in gauged WZW models,” Mod. P...

1992 arXiv
[14]

Pohlmeyer reduction of AdS(5) x S**5 superstring sigma model,

M. Grigoriev and A. A. Tseytlin, “Pohlmeyer reduction of AdS(5) x S**5 superstring sigma model,” Nucl. Phys. B 800, 450 (2008) [arXiv:0711.0155 [hep-th]]

2008 arXiv
[15]

Scalar ﬁelds on λ-deformed cosets,

O. Lunin and W. Tian, “Scalar ﬁelds on λ-deformed cosets,” Nucl. Phys. B 938, 671 (2019) [arXiv:1808.02971 [hep-th]]

2019 arXiv
[16]

The Out er automorphic WZW orbifolds on so(2n), including ﬁve triality orbifolds on so(8),

O. Ganor, M. B. Halpern, C. Helfgott and N. A. Obers, “The Out er automorphic WZW orbifolds on so(2n), including ﬁve triality orbifolds on so(8),” JHE P 0212, 019 (2002) [hep-th/0211003]

2002 arXiv
[17]

On space-time interpretatio n of the coset models in D < 26 critical string theory,

E. S. Fradkin and V. Y. Linetsky, “On space-time interpretatio n of the coset models in D < 26 critical string theory,” Phys. Lett. B 277, 73 (1992)

1992
[18]

A Superstring theory in four curved space-time dimensions,

I. Bars and K. Sfetsos, “A Superstring theory in four curved space-time dimensions,” Phys. Lett. B 277, 269 (1992) [hep-th/9111040]. 23

1992 arXiv

Pith tools

Reviewed August 14, 2026 · model on record in the stance chip above.

[1] [1]

Integrable asymmet ric λ-deformations,

S. Driezen, A. Sevrin and D. C. Thompson, “Integrable asymmet ric λ-deformations,” JHEP 1904, 094 (2019) [arXiv:1902.04142 [hep-th]]

arXiv 2019

[2] [2]

Yang-Baxter sigma models and dS/AdS T duality,

C. Klimcik, “Yang-Baxter sigma models and dS/AdS T duality,” JHEP 0212, 051 (2002), hep-th/0210095; C. Klimcik, “On integrability of the Yang-Baxter sigma-model,” J. Math . Phys. 50, 043508 (2009), arXiv:0802.3518; C. Klimcik, “Integrability of the bi-Yang-Baxter sigma-model,” Lett. Math. Phys. 104, 1095 (2014), arXiv:1402.2105; C. Klimcik, “Poisson–Lie T...

arXiv 2002

[3] [3]

An integrable deformation of the AdS5 x S5 su- perstring action,

F. Delduc, M. Magro and B. Vicedo, “An integrable deformation of the AdS5 x S5 su- perstring action,” Phys. Rev. Lett. 112, no. 5, 051601 (2014), [arXiv:1309.5850[hep- th]]; “Derivation of the action and symmetries of the q-deformed AdS5 × S5 superstring,” JHEP 1410, 132 (2014), [arXiv:1406.6286[hep-th]]

arXiv 2014

[4] [4]

S-matrix for strings on η-deformed AdS5 x S5,

G. Arutyunov, R. Borsato and S. Frolov, “S-matrix for strings on η-deformed AdS5 x S5,” JHEP 1404, 002 (2014) [arXiv:1312.3542[hep-th]]; B. Hoare, R. Roiban and A. A. Tseytlin, “On deformations of AdSn x Sn super- cosets,” JHEP 1406, 002 (2014) [arXiv:1403.5517[hep-th]]; O. Lunin, R. Roiban and A. A. Tseytlin, “Supergravity backgrounds for defor- mations ...

arXiv 2014

[5] [5]

Integrable interpolations: From exact CFTs to no n-Abelian T-duals,

K. Sfetsos, “Integrable interpolations: From exact CFTs to no n-Abelian T-duals,” Nucl. Phys. B 880, 225 (2014) [arXiv:1312.4560[hep-th]]

arXiv 2014

[6] [6]

Integrab le Deformations of Strings on Symmetric Spaces,

T. J. Hollowood, J. L. Miramontes and D. M. Schmidtt, “Integrab le Deformations of Strings on Symmetric Spaces,” JHEP 1411, 009 (2014), [arXiv:1407.2840[hep-th]]; T. J. Hollowood, J. L. Miramontes and D. M. Schmidtt, “An Integrab le Defor- mation of the AdS5 × S5 Superstring,” J. Phys. A 47, no. 49, 495402 (2014) [arXiv:1409.1538[hep-th]]. K. Sfetsos and ...

arXiv 2014

[7] [7]

Integrable λ-deformations: Squash- ing Coset CFTs and AdS5×S5,

S. Demulder, K. Sfetsos and D. C. Thompson, “Integrable λ-deformations: Squash- ing Coset CFTs and AdS5×S5,” JHEP 1507, 019 (2015), [arXiv:1504.02781[hep-th]]

arXiv 2015

[8] [8]

Generalised integr able λ– and η- deformations and their relation,

K. Sfetsos, K. Siampos and D. C. Thompson, “Generalised integr able λ– and η- deformations and their relation,” Nucl. Phys. B 899, 489 (2015), [arXiv:1506.05784 [hep-th]]; Y. Chervonyi and O. Lunin, “Generalized λ-deformations of AdS p× Sp,” Nucl. Phys. B 913, 912 (2016), [arXiv:1608.06641 [hep-th]]; 22

arXiv 2015