Vertex 1 · DELL
Double elliptic system
ℰp × ℰx
Elliptic dependence on both momentum and position. This is the top vertex of the hierarchy.
Integrable System
Original construction. Braden–Marshakov–Mironov–Morozov (1999/2000), §5, construct the classical two-particle double-elliptic Hamiltonian. Koroteev–Shakirov (2019/2020) propose the quantum many-body operators. [102] [31]
Integrability. After removing the centre of mass, the original classical system has one degree of freedom. For the many-body theta-function approach, Aminov–Braden–Mironov–Morozov–Zotov prove the identities underlying three-particle Poisson commutativity (§4). [102] [104]
Quantum status. Commutativity of the general Koroteev–Shakirov family is Conjecture 1.1 in its construction paper, with perturbative checks. A proof of that full statement is unknown in the sources collected here; contributions are welcome. [31]
- Opers
- unknown
- Baxter relation
- unknown
- Spin system
- unknown
- Finite-rank algebra
- unknown
- Large-rank algebra
- unknown
Quantum Hamiltonians and the spectral problem
Conjecture in the reviewKoroteev–Shakirov introduce quantum DELL Hamiltonians and an elliptic-genus construction of candidate eigenfunctions. The review keeps the general spectral statement as Conjecture 3.8 and reports perturbative evidence for commutativity.
[31]
Lax and large-N constructions
ConstructionGrekov–Zotov develop a characteristic determinant, a Manakov triple, and a large-N operator construction. The double-elliptic DAHA entry is unknown.
[20] [21]
Classical origins and limits
BackgroundThe classical constructions arise from generalized Mukai–Sklyanin algebras and compactified six-dimensional gauge theories. Double Inozemtsev limits and the status review give further context.
[1] [2] [27] [19] [39]
DELL spectral surface and categorical algebras
CandidateBraden–Hollowood’s four-torus is an abelian surface containing the spectral curve. Rains’s elliptic DAHA sheaf algebras and noncommutative surface constructions provide candidate frameworks. Identifying their parameters, surface geometry, and commuting operators with DELL is an open problem; the rationally ruled geometry of the 2019 construction requires an identification or extension.
[2] [31] [78] [79]
Quantization of symplectic surfaces
Geometric frameworkEtingof–Oblomkov construct formal symmetric-power deformations under a vanishing hypothesis. Dolgushev–Etingof formulate the broader unobstructedness statement. Kontsevich distinguishes formal and semi-formal quantization, including the obstruction for projective abelian varieties with nonzero Poisson structure. An affine, sheaf, or categorical realization must be specified.
[91] [92] [93]
Question for contributors: which surface and algebra or category realize the DELL operators and their known limits? The target is a distinguished commuting Hamiltonian family; at a classical specialization the full center can describe the entire phase space. The oper, Baxter, and spin entries remain unknown.
Vertex 2 · dual eRS
Dual elliptic Ruijsenaars–Schneider
ℰp × ℂx×
The elliptic q-oper vertex, with XYZ in the magnetic frame.
Integrable System
Original construction. Braden–Marshakov–Mironov–Morozov (1999/2000), §4, give the classical two-particle Hamiltonian dual to elliptic Ruijsenaars–Schneider: elliptic in momentum and trigonometric in position. [102]
Integrability. The explicit canonical duality establishes the reduced one-degree-of-freedom case. Marshakov, §3.3, describes the extension of the theta-function commutativity argument to the elliptic-RS spectral curve; the detailed derivation in §3.2 treats elliptic CM. [102] [103]
Quantum construction. Mironov–Morozov give explicit dual elliptic-RS Hamiltonians and explain their relation to the Koroteev–Shakirov degeneration. A general quantum integrability proof for the full dual family is unknown in the sources collected here. [39]
- Baxter relation
- Q𝔔-system [22]
- Finite-rank algebra
- el.trig.DAHAℏ,c,p
- Large-rank algebra
- eDIM!ℏ,q,p
Elliptic q-opers, XYZ, and dual eRS
Announced in the reviewThe review announces a nondegenerate SL(n) XYZ/elliptic q-oper correspondence (Theorem 2.12), and a dual-eRS description for a special class of opers (Proposition 2.13). Both are attributed to “Elliptic opers,” listed as forthcoming.
[22]
Elliptic algebra background
Related constructionSaito constructs elliptic Ding–Iohara operators and commuting elliptic Macdonald families. These are relevant sources for eDIM, but do not establish the particular mirror-marked eDIM! or every identification at this vertex.
[57] [58]
Elliptic DAHA sheaf algebras
Construction; candidate identificationRains constructs elliptic Hecke and DAHA sheaf algebras, their spherical versions, and Fourier transforms. These provide geometric algebra realizations for comparison with the elliptic vertices. Matching the mirror-marked algebra and its parameters is a candidate identification.
[78]
Elliptic bispectrality and modular transforms
Trace and transform resultsQuantum-affine traces satisfy MR, dual MR, qKZB, and dual qKZB equations. Felder–Varchenko develop the qKZB heat transform and its modular properties; elliptic-gamma identities supply the SL(3,Z) structure. These results give a connection layer alongside the elliptic-oper correspondence.
[69] [70] [85] [86]
Question for contributors: identify the elliptic-oper, trace-function, and sheaf-algebra descriptions under an explicit parameter dictionary. A public version of “Elliptic opers” [22] is welcome; its current link leads to the review’s announcement.
Vertex 3 · eRS
Elliptic Ruijsenaars–Schneider
ℂp× × ℰx
Elliptic difference operators; the affine Laumon K-theory vertex.
Integrable System
Original construction. Ruijsenaars–Schneider (1986) introduce the relativistic Calogero–Moser family, including the elliptic model. [100]
Integrability. Ruijsenaars (1987) constructs mutually commuting quantum difference operators and proves Poisson commutativity of their classical counterparts using elliptic-function identities. This supplies the foundational type-A integrability proof. [101]
- Opers
- unknown
- Baxter relation
- unknown
- Spin system
- unknown
- Finite-rank algebra
- trig.el.DAHAℏ,c,p [6]
- Bispectral equations
- MR, dual MR, qKZB, and dual qKZB for normalized trace functions [69] [70]
Difference-elliptic operators
ConstructionCherednik’s difference-elliptic construction supplies the operator-theoretic source cited for this DAHA entry in §3.6.
[6]
Affine Laumon functions and eRS eigenfunctions
Conjectural spectral identificationBullimore–Kim–Koroteev check the defect partition functions as eRS eigenfunctions in an instanton expansion. Shiraishi identifies a non-stationary Ruijsenaars series with affine Laumon Euler characteristics and conjectures the stationary eigenfunction limit.
[5] [62]
Elliptic DIM and commuting families
ResultSaito provides a free-field realization of the elliptic Macdonald operator and constructs commuting families using elliptic DIM and the elliptic Feigin–Odesskii algebra.
[57] [58]
The elliptic DIM reference in the 2024 handout
ResultGhoneim–Kozçaz–Kurşun–Zenkevich relate elliptic DIM to four-dimensional gauge-theory network constructions and exhibit its decomposition into trigonometric DIM and an additional Heisenberg algebra.
[65]
Eigenvalue formula in the review
Review attributionThe review states the eRS eigenvalue formula as Theorem 3.10 and attributes it to Double Inozemtsev Limits. The formula is recorded here with that review attribution; the non-stationary Laumon and trace-function results below give their own precise spectral statements.
[19]
Affine Laumon partition functions and qKZ
Result in the stated parameter setupAwata–Hasegawa–Kanno–Ohkawa–Shakirov–Shiraishi–Yamada prove the non-stationary difference equation for the relevant affine Laumon partition functions. With the stated mass tuning and truncation, it gives the quantum affine sl₂ qKZ equation with generic spins and Jackson integral solutions.
[73]
Quantum-affine traces and affine Macdonald functions
ResultEtingof–Schiffmann–Varchenko construct normalized traces satisfying four compatible difference systems; Sun supplies full proofs in specified conventions. In affine sl₂ with the three-dimensional evaluation representation, Sun identifies traces with Felder–Varchenko functions. Rains–Sun–Varchenko prove special-value results and initial affine-Macdonald cases.
[69] [70] [71] [72]
The normalized affine-Macdonald comparison
Open identificationThe Etingof–Kirillov affine Macdonald construction and Shiraishi’s affine Laumon series give two descriptions to compare. Shiraishi proposes their equality up to normalization. The open task is an explicit parameter and grading dictionary, including the gl₁ factor, followed by a controlled stationary limit.
[87] [62] [71] [72]
Elliptic algebra and modular benchmarks
Results in the cited settingsRains supplies elliptic DAHA sheaf algebras. Arthamonov–Shakirov give an explicit elliptic A₁ spherical-DAHA model at K=2, t=−q^(−K/2), with a PSL(2,Z) action. Shakirov’s 2026 elliptic CMM identities are proved to first elliptic order; all-orders identities and precise SL(3,Z) operator formulas are further targets.
[78] [82] [84] [85] [86]
Question for contributors: can the normalized affine Laumon function be identified with the quantum-affine trace under an explicit parameter dictionary? XYZ is the expected electric-frame partner; the magnetic-frame spin construction remains unknown.
Vertex 4 · dual eCM
Dual elliptic Calogero–Moser
ℰp × ℂx
The elliptic differential-oper vertex in the November 2024 scheme.
Integrable System
Original construction. Braden–Marshakov–Mironov–Morozov (1999/2000), §3, construct the classical two-particle dual of elliptic Calogero–Moser, with elliptic momentum dependence and rational position dependence. [102]
Integrability. Marshakov (1999/2000), §3.2, proves Poisson commutativity of the many-body dual theta-function Hamiltonians: their ratios depend only on the original particle positions. Equations (28)–(30) give the determinant formula and the reduced symplectic structure. [103]
- Baxter relation
- unknown
- Spin system
- Elliptic Gaudin (eGaudin) [22]
- Finite-rank algebra
- unknown
- Large-rank algebra
- unknown
Elliptic opers and the proposed correspondence
Announced programmeThe review assigns elliptic G-opers and eGaudin to this vertex and attributes their development to the ongoing elliptic-opers project. It does not provide a separate public proof for this vertex.
[22]
An elliptic complex-rank algebra
CandidateGlobal Cherednik algebras exist for smooth curves, with a Hamiltonian-reduction construction. Interpolation of the particle number in Deligne categories suggests an elliptic large-rank algebra. A filtered presentation, its central parameters, and the relation to the reflected eCM realization remain to be constructed.
[75] [76] [77]
Elliptic KZB and Casimir connections
Connection-level resultToledano Laredo–Yang construct a DDCA-valued elliptic Casimir connection. Theorem 6.9 identifies it with KZB under type-A rank duality, up to a specified closed one-form. This is a connection-level comparison relevant to an extension of the Diamond; identifying it with the elliptic-oper entry is a further task.
[81]
Question for contributors: give an explicit elliptic algebra and degeneration maps compatible with the dual eCM polarization. The Baxter and algebra entries in the handout remain unknown.
Vertex 5 · tRS
Trigonometric Ruijsenaars–Schneider
ℂp× × ℂx×
The central vertex: q-opers, XXZ Bethe equations, quantum K-theory, and DAHA.
Integrable System
Original construction. Ruijsenaars–Schneider (1986) introduce the trigonometric/hyperbolic relativistic many-body system as part of their Calogero–Moser generalization. [100]
Integrability. Ruijsenaars (1987) proves commutativity of the quantum difference Hamiltonians and Poisson commutativity of the classical integrals. The trigonometric model is a specialization of this construction. [101]
- Bispectral equations
- Bispectral quantum KZ and tRS eigenvalue equations [68]
Opers and quantum/classical duality
ResultFor the specified nondegenerate, twisted opers, QQ equations encode Bethe solutions. In type A, the canonical oper description gives a tRS Hamiltonian level set. The exact rank, singularity, and nondegeneracy assumptions are in the linked papers.
[14] [29] [34]
Quantum K-theory and Baxter operators
ResultQuantum multiplication for cotangent flag varieties is described by tRS relations. For cotangent Grassmannians, quantum multiplication by the exterior-algebra tautological class gives the XXZ Baxter operator. Vertex functions also connect qKZ and tRS.
[30] [48] [32] [37]
Stable spherical DAHA and Hilbert schemes
ResultSchiffmann–Vasserot identify the stable spherical DAHA with the elliptic Hall algebra and realize its action on equivariant K-theory of Hilbert schemes. Ding–Iohara supplies the current-algebra construction, with quantum toroidal conventions described in the survey.
[54] [55] [56] [38]
Mirror symmetry and branes
Scope: as in the papersThe oper and quiver descriptions support the bispectral/mirror correspondence. The brane/DAHA monograph treats SL(2); its category statement should not be read as an arbitrary-rank theorem.
[33] [34] [23]
DAHA and bispectral quantum KZ
Resultvan Meer–Stokman construct bispectral qKZ equations from type-GL_N DAHA and a correspondence with joint eigenfunctions of trigonometric Ruijsenaars operators. Suitable specializations recover symmetric Macdonald polynomials.
[68]
Dynamical equations and the Toda direction
ResultEtingof–Varchenko construct dynamical Weyl groups and compatible dynamical difference equations for KZ and qKZ. In type A₁, Cherednik–Orr develop nil-DAHA, q-Whittaker functions, and q-Toda equations. Compatibility of a chosen bispectral transform with a Toda limit is a concrete extension to study.
[89] [83]
Elliptic modular deformations
Specified A₁ settingsThe elliptic A₁ spherical-DAHA model at K=2 has an explicit PSL(2,Z) action. The elliptic CMM identities provide a related integral-transform problem, with a first-order proof in the elliptic parameter.
[82] [84]
Contributions comparing the bispectral transform with the nil/Toda limit are welcome.
Vertex 6 · eCM
Elliptic Calogero–Moser
ℂp × ℰx
Elliptic differential operators; the cohomological affine Laumon vertex.
Integrable System
Original construction. Calogero (1975) introduces the elliptic pair-potential extension of the many-body system. [98]
Classical integrability. Perelomov (1977) proves involutivity of the classical integrals. Krichever (1980) gives a Lax representation with spectral parameter and an algebraic-geometric integration of the elliptic particle dynamics through the KP equation. [105] [99]
Quantum integrability. Cherednik constructs elliptic quantum many-body operators. Etingof–Felder–Ma–Veselov give a commuting-Hamiltonian construction using elliptic Dunkl operators, including the usual Weyl-group elliptic Calogero–Moser systems. [7] [74]
- Opers
- unknown
- Baxter relation
- unknown
- Spin system
- unknown
- Finite-rank algebra
- rat.el.DAHAℏ,c,p; global Cherednik/Dunkl realization [7] [74] [75]
- Large-rank algebra
- unknown
- Eigenfunctions
- Normalized affine Laumon generating functions for a non-stationary operator [53]
Elliptic many-body operators
ConstructionCherednik’s elliptic quantum many-body and double affine KZ paper is the operator-theoretic reference assigned to this entry in the review.
[7]
Affine Laumon eigenfunctions
Non-stationary resultNeguț’s Affine Laumon spaces and integrable systems, Theorem 1.5, identifies the Chern-polynomial generating function with an eigenfunction of a non-stationary affine Calogero–Moser operator, after an explicit normalization. His ordinary Laumon construction gives the Calogero–Sutherland eigenfunctions at vertex 8.
[53] [42]
The qq-character approach
Related approachThe BPS/CFT papers develop qq-characters and their BPZ/KZ differential equations, providing the gauge-theory approach cited in the review’s discussion of eCM.
[43] [44]
Elliptic Dunkl operators and the critical twist
ResultEtingof–Felder–Ma–Veselov construct commuting elliptic Calogero–Moser Hamiltonians using elliptic Dunkl operators. Their geometric realization uses spherical global sections of an elliptic Cherednik sheaf at the critical twist.
[74] [75]
Complex-rank interpolation
CandidateGlobal Cherednik algebras for curves and Deligne-category interpolation provide a candidate for the large-rank elliptic algebra. The tasks are explicit relations, a PBW statement, and degeneration to the multiplicative and additive curve realizations, with central quotients specified.
[75] [76] [77] [64] [80]
Elliptic Casimir and KZ connections
Connection-level resultOn zero-weight spaces of suitable small DDCA modules, Theorem 5.3 of Toledano Laredo–Yang gives a rational Cherednik action and compares elliptic Casimir and elliptic KZ connections up to a scalar one-form. The construction supplies a precise algebra-to-connection comparison with its module hypotheses.
[81]
Question for contributors: construct an explicit elliptic complex-rank presentation and identify its action on the affine Laumon functions. The oper, Baxter, magnetic-frame spin, and large-rank algebra entries remain unknown.
Vertex 7 · rRS
Rational Ruijsenaars–Schneider
ℂp× × ℂx
The trigonometric-oper / rational-RS vertex in the magnetic frame.
Integrable System
Original construction. Ruijsenaars–Schneider (1986) introduce the rational relativistic many-body system within their family of Calogero–Moser generalizations. [100]
Integrability. Ruijsenaars (1987) proves quantum commutativity and classical Poisson commutativity; the rational specialization gives the rRS Hamiltonians and their commuting integrals. [101]
- Opers
- Trigonometrically twisted G-opers [34]
- Baxter relation
- qqt-system [34]
- Spin system
- Trigonometric Gaudin (tGaudin) [34]
- Finite-rank algebra
- tCAℏ,c(x, Y) [8]
- Large-rank algebra
- unknown
Oper coordinates and degenerations
ResultThe Zoo of Opers and Dualities treats the lower four vertices in type A. Its trigonometric-oper description connects rRS with the trigonometric Gaudin model and fits into the degenerations of the tRS picture.
[34]
rRS/tCM duality
Specified real formsFehér and collaborators establish rational-Ruijsenaars/Sutherland dualities by symplectic reduction, for the real forms and parameter ranges specified there. These complement the complex oper description and bispectral dualities.
[11] [12] [40]
KZ and dynamical equations
Connection-level resultsTarasov–Varchenko show that KZ and dynamical equations exchange under (gl_k,gl_n) duality. Etingof–Varchenko’s dynamical Weyl groups produce compatible dynamical difference equations for trigonometric KZ. These give rank-duality and compatibility data alongside the oper description.
[88] [89]
tGaudin here is the magnetic-frame partner. The electric-frame partner of rRS is XXX. The large-rank algebra is unknown.
Vertex 8 · tCM
Trigonometric Calogero–Moser
ℂp × ℂx×
Additive difference opers, XXX, and the affine Yangian.
Integrable System
Original construction. Sutherland (1971) introduces the quantum many-body problem with inverse-sine-squared interaction on a circle, the trigonometric Calogero–Moser (Calogero–Sutherland) system. [95]
Classical integrability. Moser (1975) gives the Lax and isospectral formulation; Perelomov (1977) proves involutivity of the classical integrals. [97] [105]
Quantum solution. Sutherland (1972) constructs the excited states and their exact energies. The commuting-integral approach through trigonometric Dunkl operators is described in Etingof’s lectures, §6.4. [96] [67]
- Baxter relation
- Qq-system [34]
- Finite-rank algebra
- tCAℏ,c(X, y) [8]
- Large-rank algebra
- Affine Yangian Yℏ,ε(ĝl₁) [59]
- Eigenfunctions
- Ordinary Laumon generating functions for Calogero–Sutherland [42]
Additive opers and quantum/classical duality
ResultReplacing the multiplicative shift by an additive shift leads to the (G, ε)-oper description. The type-A duality identifies its two coordinate descriptions with the XXX and tCM data in the magnetic frame.
[34]
Quantum cohomology and Laumon eigenfunctions
ResultGorbounov–Rimányi–Tarasov–Varchenko identify quantum cohomology of cotangent flag varieties with a Yangian Bethe algebra. Neguț proves the Calogero–Sutherland eigenfunction formula using ordinary Laumon spaces.
[61] [42]
Affine Yangian and additive degeneration
ResultTsymbaliuk studies the affine Yangian of gl₁ and its relation to quantum toroidal gl₁ through additive degeneration. This is the large-rank algebra in the diagram.
[59]
Calogero–Moser and Bethe-ansatz foundations
Handout referencesThe handout links tCM to Etingof’s lectures on Calogero–Moser geometry and representation theory, and XXX to Bethe’s 1931 spin-chain paper. These provide background for the modern oper and quantum-cohomology correspondences above.
[67] [66]
Curve realization and central parameters
Comparison problemFor the multiplicative curve, the global Cherednik construction gives the type-A trigonometric Cherednik algebra. Comparing a complex-rank realization to the affine Yangian requires an explicit choice of central extension or quotient, filtration, and normalization; these are additional data to the affine Yangian convention used here.
[75] [76] [77] [59]
Rational qKZ and dynamical differential equations
Connection-level resultTarasov–Varchenko construct dynamical differential operators compatible with rational qKZ for gl_N. This supplies a connection partner for the rational qKZ system; identifying the trigonometric Casimir convention requires its gauge and normalization.
[90]
The Yangian governing the finite-rank XXX Bethe algebra and the affine Yangian of gl₁ in the large-rank entry are distinct roles; the two citations keep them separate.
Vertex 9 · rCM
Rational Calogero–Moser
ℂp × ℂx
The rational differential endpoint: rational opers, Gaudin equations, rational Cherednik algebras, and DDCA.
Integrable System
Original construction. Calogero (1971) solves the quantum N-body problem with inverse-square pair interactions, with an optional quadratic confining term. This vertex uses the unconfined rational model. [94]
Classical integrability. Moser (1975) proves integrability of the rational system through isospectral evolution and commuting first integrals. [97]
Quantum integrability. Etingof’s lectures, §6, give the Dunkl-operator proof: invariant polynomials in commuting Dunkl operators yield a full commuting family of quantum Hamiltonians (Corollary 6.10 and the following gauge transformation). [67]
- Opers
- Rationally twisted G-opers [4] [34]
- Finite-rank algebra
- rCAℏ,c(x, y) [60] [8]
- Large-rank algebra
- DDCA — deformed double current algebra [63] [64] [80]
Differential opers and Gaudin Bethe equations
ResultBrinson–Sage–Zeitlin relate twisted Miura–Plücker opers, polynomial qq-solutions, and inhomogeneous Gaudin Bethe solutions, with explicit conditions for upgrading to Miura opers. The Zoo paper places the type-A rational-CM description in the degeneration diagram.
[4] [34]
Rational Cherednik algebra and Calogero–Moser space
ResultEtingof–Ginzburg provide a foundational construction linking symplectic reflection algebras, spherical rational Cherednik algebras, and Calogero–Moser geometry in type A.
[60]
DDCA, PBW, and Schur–Weyl duality
Type A; ranks as in the paperGuay proves PBW results for affine Yangians and deformed double current algebras, describes a degeneration between them, and constructs a Schur–Weyl functor with rational Cherednik algebras in the specified type-A ranks.
[63]
A precise large-rank realization
ResultEtingof–Kalinov–Rains construct DDCA using spherical symplectic-reflection algebras in Deligne categories, equivalently filtered ultraproducts of finite-rank spherical algebras. Their gl₁ construction supplies the large-rank interpretation alongside Guay’s type-A theory.
[64]
The rational Gaudin Bethe algebra
ResultMukhin–Tarasov–Varchenko prove that the Gaudin Hamiltonians generate the Bethe algebra for tensor powers of the vector representation of gl_N.
[41]
DDCA with matrix rank
ResultKalinov realizes matrix-rank deformed double current algebras through endomorphism algebras in Deligne categories. This extends the interpolation picture alongside the gl₁ realization of Etingof–Kalinov–Rains. Matrix rank, particle number, and interpolation parameter have distinct roles.
[80] [64]
DDCA and the connection layer
Results in specified ranksRational KZ and dynamical equations exchange under type-A rank duality. In the elliptic setting, Toledano Laredo–Yang construct a DDCA-valued Casimir connection and compare it with KZB in Theorem 6.9. The latter uses the specified Lie algebras and modules; extending that identification to the stable gl₁ realization is a further question.
[88] [81]
Question for contributors: make the connection-level and interpolation realizations compatible under explicit degeneration maps. The DDCA sources include Guay’s type-A construction, the gl₁ realization, and Kalinov’s matrix-rank extension.