REVIEW
Interface Yang-Mills, Supersymmetry, and Janus
High Energy Physics - Theory · Submitted 2 Mar 2006 · 26 references
Pith's verdict: A serious classification paper with two new explicit interface Lagrangians, but the load-bearing reduction to the seven algebraic equations is asserted rather than shown; the 16/8/4 uniqueness claim is conditional on that algebra.
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Referee report
The paper
The paper claims
The paper classifies all supersymmetric planar interfaces of N=4 super-Yang-Mills with varying gauge coupling, finding exactly three families.
The reading
What carries the argument
The load-bearing mechanism is the reduction of interface supersymmetry to seven algebraic equations (eq. (3.15), recast as (3.21)). The variables are the interface couplings $y_1$, $Y_2$, $Y_3$, $z^1_{ij}$, $z^2_{ij}$, $z^3_{ijk}$, $z^4_{ij}$ and the supersymmetry spinor $\zeta$; $Y_3$ is the complex symmetric matrix of trilinear fermionic interface couplings. The equations are solved by choosing $SU(4)$ gauge so that $Y_2=0$, by using Lemma 1 to diagonalize the complex symmetric matrix $Y_3=U D_3 U^t e^{i\theta_0}$ with $D_3$ real, non-negative, diagonal, and by working in the basis where the supersymmetry spinor points along an eigenvector of $D_3$. The number of unit eigenvalues of $D_3$, equivalently the rank of $Y_3^\dagger Y_3$, then determines how many supercharges survive, with the Clifford-algebra identities of the $\rho_i$ matrices converting the spinor constraints into purely algebraic ones.
Extended reading notes
Core claim
The central claim is a systematic, complete classification of interface supersymmetry for $N=4$ super-Yang-Mills on either side of a planar interface, with a smoothly varying gauge coupling $g(x^\pi)$, no independent interface degrees of freedom, and interface couplings restricted to local gauge-invariant operators of dimension at most three built from $\partial_\pi g$. The paper reduces the supersymmetry conditions to seven algebraic equations and solves them in closed form, up to $SU(4)$ rotations. The solutions give: $\mathcal{N}=4$ interface supersymmetry with 8 real Poincaré supercharges, $SU(2)\times SU(2)$ R-symmetry, and 16 conformal supercharges; $\mathcal{N}=2$ interface supersymmetry with 4 real Poincaré supercharges, $SO(2)\times SU(2)$ R-symmetry, and 8 conformal supercharges; and the earlier $\mathcal{N}=1$ interface theory with 2 real Poincaré supercharges, $SU(3)$ internal symmetry, and 4 conformal supercharges. Explicit Lagrangians are constructed in Section 5, and the existence of the conformal limit is tied to removing the $(\partial_\pi g)^2$ term by field rescaling. The paper also notes that the maximal-symmetry theory has precisely the symmetries of the D3-D5 brane intersection, but lacks that system's localized degrees of freedom, so a decoupling mechanism would be needed for a direct brane realization.
Load-bearing premise
The classification is complete only if the interface carries no independent degrees of freedom, if the allowed interface operators are exactly the local gauge-invariant terms of dimension at most three built from $\partial_\pi g$ and listed in (2.3), and if the supersymmetry transformation is modified only by $\delta_I\psi=(\partial_\pi g)\chi_i\phi_i$; relaxing any of these restrictions could produce additional interface theories.
Editorial extensions
If this is right
- Every supersymmetric interface CFT of this type belongs to one of the three families; the classification by rank of $Y_3^\dagger Y_3$ leaves no other possibilities.
- In each conformal limit the Poincaré supercharges are doubled, giving supergroups $\mathrm{OSP}(2,2|n)$ with $n=4,2,1$ for the maximal, $N=2$, and $N=1$ theories.
- The new theories turn on only supergravity-multiplet operators, so each provides a concrete target for constructing a ten-dimensional supersymmetric Janus-like supergravity solution.
- The recovery of the earlier $SU(3)$ interface CFT from the same algebraic system unifies the known interface constructions within a single classification.
- The symmetry match with the D3-D5 system, together with the absence of localized degrees of freedom, predicts that any holographic relation between the maximal interface theory and that brane intersection must pass through a decoupling mechanism for the 3-5 strings.
Reading between the lines
- If the interface operator list is widened beyond (2.3), for instance by adding higher-dimension operators or localized defect fields, the classification could acquire new branches; the D3-D5 hypermultiplet is a natural candidate for such a branch.
- The algebraic structure is tied to $SU(4)\cong SO(6)$, so a similar seven-equation reduction may apply to other codimension-one defects in $N=4$ SYM or to defect theories in related dimensions, where the same $\rho$-matrix identities would do the work.
- A practical next step would be to compute two-point functions or anomaly data from the explicit Lagrangians and compare them with the conjectured supergravity duals; the $SO(2)\times SU(2)$ theory has no known brane realization and would be the most surprising target.
- The conformal-limit condition (6.3) can be read as a criterion for when a defect coupling is truly marginal: the $(\partial_\pi g)^2$ term must be removable by a field rescaling, a condition that may generalize beyond this specific interface.
Original abstract
We consider theories consisting of a planar interface with $\N=4$ super-Yang-Mills on either side and varying gauge coupling across the interface. The interface does not carry any independent degrees of freedom, but is allowed to support local gauge invariant operators, included with independent interface couplings. In general, both conformal symmetry and supersymmetry will be broken, but for special arrangements of the interface couplings, these symmetries may be restored. We provide a systematic classification of all allowed interface supersymmetries. We find new theories preserving eight and four Poincar\'e supersymmetries, which get extended to sixteen and eight supersymmetries in the conformal limit, respectively with $SU(2) \times SU(2)$, $SO(2) \times SU(2)$ internal symmetry. The Lagrangians for these theories are explicitly constructe d. We also recover the theory with two Poincar\'e supersymmetries and SU(3) internal symmetry proposed earlier as a candidate CFT dual to super Janus. Since our new interface theories have only operators from the supergravity multiplet turned on, dual supergravity solutions are expected to exist. We speculate on the possible relation between the interface theory with maximal supersymmetry and the near-horizon limit of the D3-D5 system.
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 consider theories consisting of a planar interface with $\N=4$ super-Yang-Mills on either side and varying gauge coupling across the interface. The interface does not carry any independent degrees of freedom, but is allowed to support local gauge invariant operators, included with independent interface couplings. In general, both conformal symmetry and supersymmetry will be broken, but for special arrangements of the interface couplings, these symmetries may be restored. We provide a systematic classification of all allowed interface supersymmetries. We find new theories preserving eight and four Poincar\'e supersymmetries, which get extended to sixteen and eight supersymmetries in the conformal limit, respectively with $SU(2) \times SU(2)$, $SO(2) \times SU(2)$ internal symmetry. The Lagrangians for these theories are explicitly constructe d. We also recover the theory with two Poincar\'e supersymmetries and SU(3) internal symmetry proposed earlier as a candidate CFT dual to super Janus. Since our new interface theories have only operators from the supergravity multiplet turned on, dual supergravity solutions are expected to exist. We speculate on the possible relation between the interface theory with maximal supersymmetry and the near-horizon limit of the D3-D5 system.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | We consider theories consisting of a planar interface with $\N=4$ super-Yang-Mills on either side and varying gauge coupling across the interface. | background 0.62 | 0.48 | 0.04 | asserted 0.97 |
| s1 | The interface does not carry any independent degrees of freedom, but is allowed to support local gauge invariant operators, included with independent interface couplings. | background 0.79 | 0.26 | 0.04 | asserted 0.94 |
| s2 | In general, both conformal symmetry and supersymmetry will be broken, but for special arrangements of the interface couplings, these symmetries may be restored. | background 0.92 | 0.18 | 0.07 | hedged possibility 0.82 |
| s3 | We provide a systematic classification of all allowed interface supersymmetries. | contribution 0.98 | 0.94 | 0.14 | asserted 1.00 |
| s4 | We find new theories preserving eight and four Poincar\'e supersymmetries, which get extended to sixteen and eight supersymmetries in the conformal limit, respectively with $SU(2) \times SU(2)$, $SO(2) \times SU(2)$ internal symmetry. | result 0.99 | 0.96 | 0.44 | asserted 1.00 |
| s5 | The Lagrangians for these theories are explicitly constructe d. | contribution 0.64 | 0.94 | 0.07 | asserted 1.00 |
| s6 | We also recover the theory with two Poincar\'e supersymmetries and SU(3) internal symmetry proposed earlier as a candidate CFT dual to super Janus. | result 0.95 | 0.67 | 0.11 | asserted 0.99 |
| s7 | Since our new interface theories have only operators from the supergravity multiplet turned on, dual supergravity solutions are expected to exist. | interpretation 0.98 | 0.17 | 0.08 | hedged possibility 0.96 |
| s8 | We speculate on the possible relation between the interface theory with maximal supersymmetry and the near-horizon limit of the D3-D5 system. | future work 0.62 | 0.27 | 0.06 | speculative 1.00 |
What was examined, and what was not
- arXiv listing abstract v1
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
Figures
Figures reproduced from arXiv:hep-th/0603013 by the authors.
References
How later papers used it
82 later papers cite it
2 later papers by other authors are listed below: 1 built on it and 1 cited it as support. 1 more paper by the same authors is listed: 1 built on it.
Builds on it 2 of 4 papers with this label · 1 by the same authors
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Generalized section 6 of this paper to ask whether the Janus configuration can classically be taken to a conformally invariant limit.
Janus Configurations, Chern-Simons Couplings, And The Theta-Angle in N=4 Super Yang-Mills Theory (2008) · 0.94 · paraphrased: the licence does not allow quoting
By the same authors
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Proposed a dual gauge theory as a generalization of the interface conformal field theory discussed in this paper.
Exact half-BPS Type IIB interface solutions II: Flux solutions and multi-Janus (2007) (same authors) · 0.94 · paraphrased: the licence does not allow quoting
Cites it as support 1 paper
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Deduced from the nontrivial bosonic and fermionic bilinear operators in the dual field theory given in this paper that the scalars should have non-trivial profiles and vanish in the AdS5 asymptotic regions.
Holographic Interfaces in N=4 SYM: Janus and J-folds (2020) · 0.99 · paraphrased: the licence does not allow quoting
How the literature uses it
82 arXiv papers cite this in 138 sentences
Papers citing it · 82 sentences without a confident label
Builds on it 4 papers
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Now (generalizing section 6 of [ref] ) we would like to ask whether, classically, it is possible to take a limit in which the Janus configuration becomes conformally invariant.
Janus Configurations, Chern-Simons Couplings, And The Theta-Angle in N=4 Super Yang-Mills Theory · Conformally Invariant Limit · 0.94
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Later, the Janus field theories in [ref] were generalized to allow the theta-angle to vary which is holographicallly dual to the axion field, and were also applied to construct three-dimensional Chern-Simons theories with $𝒩$ = 4 supersymmetries in [ref] .
Supersymmetric Janus solutions in five and ten dimensions · Introduction · 0.82
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In section 8, a dual gauge theory is proposed as a generalization of the interface conformal field theory discussed in [ref] .
Exact half-BPS Type IIB interface solutions II: Flux solutions and multi-Janus · Introduction · 0.94
Uses its method or tool 2 papers
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The key step is to generalize $T(SU(n))$ and its close cousins, which we do using Janus domain walls [ref] .
S-Duality of Boundary Conditions In N=4 Super Yang-Mills Theory · Introduction · 0.84
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For example, application of the methods developed in [ref] could be used to calculate correlation functions in the presence of the interface/defect. * As the ABJM theory enjoys a well-understood field theoretic CFT description, one may classify the possible interface/defect terms along the lines of [ref] and [ref] , establish their symmetries, and derive the associated supergravity solutions. * In Type IIB theory, the simplest Janus solution breaks all supersymmetries, has a non-trivial dilaton profile, and vanishing 3-form flux fields.
Janus solutions in M-theory · Discussion · 0.81
Compares with it 5 papers
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We easily recover the results in Ref. [ref] .
Janus and Multifaced Supersymmetric Theories · Additional Susy Breaking Janus · 0.90
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To compare with [ref] , we will look for solutions to eq:susyconditions satisfying the following input assumptions: first, the solutions exist in Minkowski spacetime with the trivial metric, and they preserve a three-dimensional Poincare symmetry.
Supergravity Backgrounds for Four-Dimensional Maximally Supersymmetric Yang-Mills · Janus examples · 0.96
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The symmetries of these solutions nicely match with the largest symmetric SYM interfaces classified in [ref] .
Type IIB S-folds: flat deformations, holography and stability · Flat deformations of type IIB S-folds: four-dimensional picture · 0.81
Cites it as support 1 paper
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Furthermore, from the presence of nontrivial bosonic and fermionic bilinear operators in the dual field theory [ref] , we deduce that the corresponding scalars, $α$ and $χ$, should both have non-trivial profiles and vanish in the AdS$_5$ asymptotic regions.
Holographic Interfaces in N=4 SYM: Janus and J-folds · The five-dimensional Janus · 0.99
Cites it as background 44 papers
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Later, Janus gauge theories were constructed more systematically in [ref] .
Supersymmetric Janus solutions in five and ten dimensions · Introduction · 0.93
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It was introduced in [ref] and generalized in [ref] .[See also [ref] for other studies of the supersymmetric Janus theory.] The holographic dual background corresponds to a solution with $Σ$ an infinite strip, which is shown in Figure [ref].
Holographic duals of 3d S-fold CFTs · Supergravity solutions · 0.88
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Via the AdS/CFT correspondence [ref] , Janus solutions of supergravity theories [ref] provide a simple and explicit realisation of interfaces in dual field theories [ref] .
S-folds and $AdS_{3}$ flows from the D3-brane · Introduction · 0.94
Discussion
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