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REVIEW 2 major objections 4 minor 68 references

The boundary-driven multispecies harmonic process is Yang-Baxter integrable, with its Markov generator equal to the logarithmic derivative of a double-row transfer matrix.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-01 00:18 UTC pith:YVZYR6LE

load-bearing objection Genuinely new algebraic construction of an integrable multispecies harmonic process, but the boundary Hamiltonian as printed has a sign error in the diagonal log term that breaks the identification in Theorem 4.8. the 2 major comments →

arxiv 2607.26262 v1 pith:YVZYR6LE submitted 2026-07-28 math-ph cond-mat.stat-mechmath.MPmath.PR

The boundary-driven multispecies harmonic process

classification math-ph cond-mat.stat-mechmath.MPmath.PR MSC 82B2360J2782C2281R12
keywords multispecies harmonic processboundary-driven Markov chainYang-Baxter integrabilitydouble-row transfer matrixstochastic R-matrixMarkov dualityopen Heisenberg spin chainq-Hahn rational limit
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

The paper introduces a continuous-time Markov chain on a one-dimensional chain where each site holds an unbounded number of particles of M species, with symmetric bulk jumps and boundary reservoirs that inject and remove particles. It claims that this process is Yang-Baxter integrable: the Markov generator is exactly the Hamiltonian of an open higher-rank rational Heisenberg spin chain with non-compact representations, obtained as one half of the logarithmic derivative of a double-row transfer matrix at the permutation point. The rates are forced by integrability and reduce to a multispecies q-Hahn process in the q to 1 limit. From the same algebraic structure, the paper derives three dual processes — an absorbing particle model, a hidden-parameter model, and a heat-conduction model — so that stationary-state moments reduce to absorption probabilities or to simpler representations.

Core claim

Theorem 4.8 identifies the generator H of the boundary-driven multispecies harmonic process as H = 1/2(∂_x ln T(x)|_{x=0} + h(M) I), where T(x) is the double-row transfer matrix built from the factorised R-matrix (3.127) and the off-diagonal K-matrices (4.27), and h(M) is the M-th harmonic number. Equivalently, the process is Yang-Baxter integrable, with boundary reservoirs encoded by similarity-transformed diagonal K-matrices. The R-matrix factorises into two operators corresponding to left- and right-moving particles; the bulk rates are the rational limit of q-Hahn weights. If the identification holds, Theorems 5.3, 5.8 and 5.11 establish duality with an absorbing model, a hidden-parameter

What carries the argument

The central objects are the factorised R-operator R(x-y)=P R+(x2|y1,y2) R-(x1,x2|y1), expressed through M pairs of Heisenberg oscillators, and the double-row transfer matrix T(x) formed with a pair of off-diagonal K-matrices solving the reflection equation. The two factors in the R-matrix generate, respectively, left and right particle jumps; logarithmic differentiation at x = 0 yields the stochastic Hamiltonian density, and the same operation on T(x) reproduces the full boundary generator. The K-matrices arise from diagonal solutions of the reflection equation conjugated by exponentials of gl(M+1) generators, which turns them into non-diagonal boundary reservoirs.

Load-bearing premise

The proof rests on infinite-dimensional trace computations (identities (4.41)-(4.48)) whose convergence and interchange of sums, derivatives, and integrals are not established; the dual generators are also only defined on polynomials, with their full domain left open.

What would settle it

Compute the double-row transfer matrix T(x) for M=2, s=1/2 on a truncated Fock space with total occupancy bounded by K, form H_K = 1/2(∂_x ln T(x)|_{x=0} + h(2) I), and compare matrix elements with the generator L from (2.6) restricted to the same truncation; if the two differ for any finite K, the identification is wrong. Alternatively, find a parameter choice where the sum in (4.41) diverges.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • The generator possesses a commuting family of conserved operators, so the process is exactly solvable via Bethe-ansatz methods.
  • Moments of the non-equilibrium stationary measure are expressed by absorption probabilities of finitely many dual particles.
  • Three Markov dual processes are constructed with explicit polynomial duality functions: an absorbing dual, a hidden-parameter model, and a heat-conduction model.
  • When left and right boundary parameters coincide, the stationary measure is a reversible product of Negative-Multinomial measures.
  • Isospectral triangular Hamiltonians reduce the steady-state problem to a factorised ground state, making closed-form stationary measures accessible.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Because the trace identities in Section 4.2 assume interchange of infinite sums and derivatives, a fully rigorous treatment for all s>0 would require a functional-analytic domain for the dual generators; the present proof is algebraic and conditional on those analytic steps.
  • The factorisation of the R-matrix uses an infinite-dimensional auxiliary space even when the full matrix truncates to finite dimensions; an immediate check is to compare finite-dimensional truncations of the transfer-matrix Hamiltonian with the known multispecies stirring process.
  • The same construction suggests a wider classification of stochastic integrable boundaries for non-compact vertex models: any reservoir described by a similarity-transformed diagonal K-matrix satisfying the reflection equation should yield an integrable boundary-driven process.
  • The dualities could be used to probe hydrodynamic limits or large-deviation principles for the multispecies harmonic process, since the absorbing dual process involves finitely many particles.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

2 major / 4 minor

Summary. The paper introduces the boundary-driven multispecies harmonic process, a continuous-time Markov chain with M species and unbounded occupancy, and claims its generator is the Hamiltonian of an integrable open gl(M+1) spin chain. A factorised R-matrix is derived in Theorem 3.3, off-diagonal K-matrices are obtained in Section 4.1, and Theorem 4.8 identifies the generator with the logarithmic derivative of Sklyanin's double-row transfer matrix. Three dual processes are defined and duality theorems are stated. The constructions are algebraic and reduce correctly to known models (M=1 harmonic process, multispecies stirring process, SSEP).

Significance. If established, the result would be a significant contribution to integrable stochastic particle systems: a boundary-driven multi-species process with unbounded occupancy whose reservoirs are integrable, providing a new route to exact stationary properties via dualities. The paper's strengths are the explicit operator form of the R-matrix, rates fixed by the Yang-Baxter equation without fitted parameters, and external checks through reductions to known models. The three dualities are plausible and constitute a useful toolbox. However, the central identification is currently defective by a boundary sign error, and the analytic justification of the transfer-matrix calculation is incomplete.

major comments (2)
  1. [Proposition 4.9 and Lemma 4.11, Eqs. (4.51), (4.62)] The diagonal element of the boundary Hamiltonian is stated as h_s(|m|)+log(1-|β|). This is inconsistent with Eq. (2.24), which requires h_s(|m|)-log(1-|β|), and with the corresponding generator (2.13). The proof of Lemma 4.11 actually yields the minus sign: the term S evaluated around (4.77) is log(1-|β|) after correcting the displayed chain (which should read -log(1+Σρ)=log(1-|β|)), and O' equals the first term minus S. Thus (4.51) and (4.62) should carry -log. As written, Theorem 4.8's boundary Hamiltonian does not coincide with the stochastic Hamiltonian H of Section 2, so the central integrability identification is not established. This is a local but load-bearing sign error.
  2. [Section 4.2, Eqs. (4.41)-(4.48)] The extraction of H from the logarithmic derivative of T(x) uses traces over an infinite-dimensional auxiliary Fock space and interchanges of ∂_x with the trace and infinite sums (e.g., (4.41) and term-by-term differentiation at x=0). No convergence or justification is given. Since Theorem 4.8's boundary terms come from these traces, this is load-bearing. Please provide a rigorous justification or state precisely the formal/algebraic setting in which (4.39) is understood.
minor comments (4)
  1. [Eq. (2.43)] The right boundary generator of the hidden parameter model uses ρ_l in the argument f(αθ_N+(1-α)ρ_l); this should likely be ρ_r.
  2. [Remark 2.4] The domain of the hidden parameter generator is left open. Since duality theorems in Section 5 are stated for polynomial functions, please specify the domain or dense subspace on which the generator and duality relations are proven.
  3. [Eq. (3.139)] The upper limit of the sum contains N, but the index is over M species; this appears to be a typo for M.
  4. [Eq. (4.77)] The displayed identity '-log((1+|β|)/(1-|β|)) = log(1-|β|)' is not correct as written. If the intended identity is '-log(1+Σρ) = log(1-|β|)', it should be rewritten to avoid ambiguity.

Circularity Check

0 steps flagged

No significant circularity: the central Yang-Baxter construction is self-contained; noted sign and analytic issues are correctness concerns, not circularity.

full rationale

The paper's central claim is that the boundary-driven multispecies harmonic generator (defined independently in Section 2) is reproduced as the logarithmic derivative of a Sklyanin double-row transfer matrix built from an R-matrix and K-matrices solved from the Yang-Baxter relation. The R-matrix is derived constructively in Section 3 by solving the RLL/Yang-Baxter equation with explicit lemmas; the normalization (3.100) is a gauge choice making R(0)=P and the matrix elements stochastic, not a parameter fitted to the target generator. The K-matrix is likewise solved from the boundary Yang-Baxter equation in Section 4.1, and the parameters q1/q2 in (4.34) are free normalization parameters chosen so that the logarithmic derivative gives the boundary ψ-difference; the physical boundary parameters β enter only through the similarity transformation D_ρ and are not fitted. Thus the identification is not circular by construction: the process rates are fixed independently, and the transfer-matrix computation is checked componentwise in Proposition 4.9 rather than assumed. Self-citations to prior work by the authors (e.g. [27], [65], [67]) are methodological or used for analogous proof steps, not as an unverified uniqueness theorem or ansatz import. External benchmarks are also present: the M=1 harmonic process, the q→1 limit of the q-Hahn process, and the multispecies stirring/SSEP limits. These anchor the construction independently of the present paper's conclusions. The manuscript does contain passage-flagged limitations and internal inconsistencies, but these are not circularity: Remark 2.4 leaves the domain of the hidden-parameter generator open; Section 4.2 uses infinite trace manipulations (4.41)-(4.48) without convergence justification; and the diagonal sign in Proposition 4.9 (ψ(|m|+2s)−ψ(2s)+log(1−|β|)) is inconsistent with the generator in (2.24), which requires −log(1−|β|). These are correctness/rigor concerns about whether Theorem 4.8 is established as written, not reductions of a prediction to its own input. Accordingly the circularity score is 0.

Axiom & Free-Parameter Ledger

0 free parameters · 4 axioms · 0 invented entities

The model parameters s and β are inputs defining the process, not fitted quantities, so no free parameters are counted. The main external assumptions are the standard QISM framework plus domain/convergence assumptions for infinite-dimensional Fock-space computations and the dual generators. No new particles, forces or conserved entities are postulated.

axioms (4)
  • domain assumption The Fock-space representation of gl(M+1) with Dynkin labels (μ1, μ2, ..., μ2), μ1 < μ2, is irreducible for 2s > 0.
    Invoked in Section 3.5 and used throughout the transfer matrix construction; for 2s ≤ 0 the representation is reducible and the stochastic Hamiltonian interpretation changes.
  • domain assumption The Markov generators on the countable or continuous state spaces are conservative and well-defined, and the dual generators act on polynomials.
    Remark 2.4 explicitly leaves the domain of the hidden-parameter generator open; the trace computations in Section 4.2 presuppose convergence without proof.
  • standard math Sklyanin's double-row transfer matrix construction yields commuting transfer matrices when the R-matrix and K-matrices satisfy RLL and boundary Yang-Baxter equations.
    This is the framework on which Theorem 4.8 relies.
  • standard math Hypergeometric summation identities, including Beta integrals, Lauricella functions and identities such as (3.120), (4.67) and (4.74), are valid in the required parameter ranges.
    These identities are used in the component computations of the R-matrix and the boundary Hamiltonian, e.g. Propositions 3.14 and 4.9 through Lemma 4.11.

pith-pipeline@v1.3.0-alltime-deepseek · 56309 in / 9880 out tokens · 101123 ms · 2026-08-01T00:18:38.736667+00:00 · methodology

0 comments
read the original abstract

We introduce the multispecies version of the harmonic process on a one-dimensional chain in contact with boundary reservoirs. This process is a continuous-time Markov chain where each site can host an unbounded number of colored particles. The symmetric bulk dynamics is put in contact with reservoirs, which inject and remove particles driving the system out-of-equilibrium. The Markov generator of the process is identified with the integrable Hamiltonian of an open rational Heisenberg spin chain of higher rank. We derive the underlying R- and K-matrices in operator form and construct the double-row transfer matrix following Sklyanin. Similar to the monospecies case the R-matrix factorises into two R-operators, each factor corresponding to left and right moving particles. We further define three dual models: an absorbing particle model, a hidden parameter model and a heat conduction model.

discussion (0)

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Reference graph

Works this paper leans on

68 extracted references · 51 linked inside Pith

  1. [1]

    Interaction of Markov processes,

    F. Spitzer, “Interaction of Markov processes,”Adv. Math.5no. 2, (1970) 246–290

  2. [2]

    T. M. Liggett,Interacting Particle Systems, vol. 276 ofGrundlehren der mathematischen Wissenschaften. Springer, 1985

  3. [3]

    Six-vertex model, roughened surfaces, and an asymmetric spin Hamiltonian,

    L.-H. Gwa and H. Spohn, “Six-vertex model, roughened surfaces, and an asymmetric spin Hamiltonian,” Phys. Rev. Lett.68no. 6, (1992) 725–728

  4. [4]

    Exactly Solvable Models for Many-Body Systems Far from Equilibrium,

    G. M. Schütz, “Exactly Solvable Models for Many-Body Systems Far from Equilibrium,” vol. 19 of Phase Transitions and Critical Phenomena, pp. 1–251. Academic Press, 2001

  5. [5]

    Non-equilibrium steady states: fluctuations and large deviations of the density and of the current,

    B. Derrida, “Non-equilibrium steady states: fluctuations and large deviations of the density and of the current,”J. Stat. Mech.2007(2007) P07023,arXiv:cond-mat/0703762 [cond-mat.stat-mech]

  6. [6]

    Nonequilibrium steady states of matrix-product form: a solver’s guide,

    R. A. Blythe and M. R. Evans, “Nonequilibrium steady states of matrix-product form: a solver’s guide,” J. Phys. A40no. 46, (2007) R333–R441,arXiv:0706.1678 [cond-mat.stat-mech]

  7. [7]

    The asymmetric simple exclusion process: an integrable model for non-equilibrium statistical mechanics,

    O. Golinelli and K. Mallick, “The asymmetric simple exclusion process: an integrable model for non-equilibrium statistical mechanics,”J. Phys. A39no. 41, (2006) 12679, arXiv:cond-mat/0611701 [cond-mat.stat-mech]

  8. [8]

    Reaction - diffusion processes, critical dynamics and quantum chains,

    F. C. Alcaraz, M. Droz, M. Henkel, and V. Rittenberg, “Reaction - diffusion processes, critical dynamics and quantum chains,”Annals Phys.230(1994) 250–302,arXiv:hep-th/9302112

  9. [9]

    The matrix product solution of the multispecies partially asymmetric exclusion process,

    S. Prolhac, M. R. Evans, and K. Mallick, “The matrix product solution of the multispecies partially asymmetric exclusion process,”J. Phys. A42no. 16, (2009) 165004,arXiv:0812.3293 [cond-mat.stat-mech]. 58

  10. [10]

    Matrix product solution to a 2-species TASEP with open integrable boundaries,

    N. Crampé, M. R. Evans, K. Mallick, E. Ragoucy, and M. Vanicat, “Matrix product solution to a 2-species TASEP with open integrable boundaries,”J. Phys. A49no. 47, (2016) 475001, arXiv:1606.08148

  11. [11]

    Integrable boundary conditions for multi-species ASEP,

    N. Crampé, C. Finn, E. Ragoucy, and M. Vanicat, “Integrable boundary conditions for multi-species ASEP,”J. Phys. A49no. 37, (2016) 375201,arXiv:1606.01018 [math-ph]

  12. [12]

    Exact solution to integrable open multi-species SSEP and macroscopic fluctuation theory,

    M. Vanicat, “Exact solution to integrable open multi-species SSEP and macroscopic fluctuation theory,” J. Stat. Phys.166no. 5, (2017) 1129–1150,arXiv:1610.08388 [cond-mat.stat-mech]

  13. [13]

    Duality for the multispecies stirring process with open boundaries,

    F. Casini, R. Frassek, and C. Giardinà, “Duality for the multispecies stirring process with open boundaries,” J. Phys. A57no. 29, (2024) 295001,arXiv:2312.15532

  14. [14]

    Stochastic six-vertex model,

    A. Borodin, I. Corwin, and V. Gorin, “Stochastic six-vertex model,”Duke Math. J.165no. 3, (2016) 563–624,arXiv:1407.6729 [math.PR]

  15. [15]

    Higher spin six vertex model and symmetric rational functions,

    A. Borodin and L. Petrov, “Higher spin six vertex model and symmetric rational functions,” Selecta Math.24(2018) 751–874,arXiv:1601.05770 [math.PR]

  16. [16]

    Stochastic Higher Spin Vertex Models on the Line,

    I. Corwin and L. Petrov, “Stochastic Higher Spin Vertex Models on the Line,”Commun. Math. Phys.343no. 2, (2016) 651–700,arXiv:1502.07374 [math.PR]

  17. [17]

    On the integrability of zero-range chipping models with factorized steady states,

    A. M. Povolotsky, “On the integrability of zero-range chipping models with factorized steady states,” J. Phys. A46no. 46, (2013) 465205,arXiv:1308.3250 [math-ph]

  18. [18]

    The q-Hahn asymmetric exclusion process,

    G. Barraquand and I. Corwin, “The q-Hahn asymmetric exclusion process,”Ann. Appl. Probab.26 no. 4, (2016) 2304–2356,arXiv:1501.03445

  19. [19]

    The q-Hahn Boson Process and q-Hahn TASEP,

    I. Corwin, “The q-Hahn Boson Process and q-Hahn TASEP,”Int. Math. Res. Not.2015no. 14, (2015) 5577–5603,arXiv:1401.3321 [math.PR]

  20. [20]

    On integrable Hamiltonians for higher spin XXZ chain,

    A. G. Bytsko, “On integrable Hamiltonians for higher spin XXZ chain,”J. Math. Phys.44(2003) 3698–3717,arXiv:hep-th/0112163

  21. [21]

    How algebraic Bethe ansatz works for integrable model,

    L. D. Faddeev, “How algebraic Bethe ansatz works for integrable model,” in Les Houches School of Physics: Astrophysical Sources of Gravitational Radiation, pp. 149–219. 1996.arXiv:hep-th/9605187

  22. [22]

    On the Yang-Baxter equation for the six-vertex model,

    V. V. Mangazeev, “On the Yang-Baxter equation for the six-vertex model,”Nucl. Phys. B882 (2014) 70–96,arXiv:1401.6494 [math-ph]

  23. [23]

    Bethe Ansatz Solution of the Asymmetric Exclusion Process with Open Boundaries,

    J. de Gier and F. H. L. Essler, “Bethe Ansatz Solution of the Asymmetric Exclusion Process with Open Boundaries,”Phys. Rev. Lett.95(2005) 240601,arXiv:cond-mat/0508707 [cond-mat.stat-mech]

  24. [24]

    Stochastic R matrix forUq(A(1) n ),

    A. Kuniba, V. V. Mangazeev, S. Maruyama, and M. Okado, “Stochastic R matrix forUq(A(1) n ),” Nucl. Phys. B913(2016) 248–277,arXiv:1604.08304 [math.QA]

  25. [25]

    One-dimensional asymmetric diffusion model without exclusion,

    T. Sasamoto and M. Wadati, “One-dimensional asymmetric diffusion model without exclusion,” Phys. Rev. E58no. 4, (1998) 4181–4190

  26. [26]

    Coloured stochastic vertex models and their spectral theory,

    A. Borodin and M. Wheeler, “Coloured stochastic vertex models and their spectral theory,” Astérisque no. 437, (2022) ,arXiv:1808.01866 [math.PR]

  27. [27]

    Non-compact quantum spin chains as integrable stochastic particle processes,

    R. Frassek, C. Giardinà, and J. Kurchan, “Non-compact quantum spin chains as integrable stochastic particle processes,”J. Stat. Phys.180(2020) 135–171,arXiv:1904.01048 [math-ph]. 59

  28. [28]

    The non-compact XXZ spin chain as stochastic particle process,

    R. Frassek, “The non-compact XXZ spin chain as stochastic particle process,”J. Phys. A52no. 33, (2019) 335202,arXiv:1904.02191 [math-ph]

  29. [29]

    Boundary Conditions for Integrable Quantum Systems,

    E. K. Sklyanin, “Boundary Conditions for Integrable Quantum Systems,”J. Phys. A21(1988) 2375–2389

  30. [30]

    Integrable approach to simple exclusion processes with boundaries. Review and progress,

    N. Crampé, E. Ragoucy, and M. Vanicat, “Integrable approach to simple exclusion processes with boundaries. Review and progress,”J. Stat. Mech.2014no. 11, (2014) P11032,arXiv:1408.5357

  31. [31]

    Bethe Ansatz and Q-operator for the open ASEP,

    A. Lazarescu and V. Pasquier, “Bethe Ansatz and Q-operator for the open ASEP,”J. Phys. A47 no. 29, (2014) 295202,arXiv:1403.6963 [math-ph]

  32. [32]

    Boundary matrices for the higher spin six vertex model,

    V. V. Mangazeev and X. Lu, “Boundary matrices for the higher spin six vertex model,”Nucl. Phys. B945(2019) 114665,arXiv:1903.00274 [math-ph]

  33. [33]

    Triangular solutions to the reflection equation forUq(ˆsln),

    D. Kolyaskin and V. V. Mangazeev, “Triangular solutions to the reflection equation forUq(ˆsln),” J. Phys. A57no. 24, (2024) 245201,arXiv:2402.05442 [math-ph]

  34. [34]

    Integrable boundaries for the q-Hahn process,

    R. Frassek, “Integrable boundaries for the q-Hahn process,”J. Phys. A55no. 40, (2022) 404008, arXiv:2205.10512 [math-ph]

  35. [35]

    Duality relations for asymmetric exclusion processes,

    G. M. Schütz, “Duality relations for asymmetric exclusion processes,”J. Stat. Phys.86no. 5, (1997) 1265–1287

  36. [36]

    De Masi and E

    A. De Masi and E. Presutti,Mathematical Methods for Hydrodynamic Limits, vol. 1500 ofLecture Notes in Mathematics. Springer, 2006

  37. [37]

    Giardinà and F

    C. Giardinà and F. Redig,Duality for Markov processes: a Lie algebraic approach, vol. 365 of Grundlehren der mathematischen Wissenschaften. Springer, Cham, 2025

  38. [38]

    From duality to determinants for q-TASEP and ASEP,

    A. Borodin, I. Corwin, and T. Sasamoto, “From duality to determinants for q-TASEP and ASEP,” Ann. Probab.42no. 6, (2014) 2314–2382,arXiv:1207.5035 [math.PR]

  39. [39]

    Long range correlations for stochastic lattice gases in a non-equilibrium steady state,

    H. Spohn, “Long range correlations for stochastic lattice gases in a non-equilibrium steady state,” J. Phys. A16no. 18, (1983) 4275

  40. [40]

    Heat flow in an exactly solvable model,

    C. Kipnis, C. Marchioro, and E. Presutti, “Heat flow in an exactly solvable model,”J. Stat. Phys. 27no. 1, (1982) 65–74

  41. [41]

    A reverse duality for the ASEP with open boundaries,

    G. M. Schütz, “A reverse duality for the ASEP with open boundaries,”J. Phys. A56no. 27, (2023) 274001,arXiv:2211.02844 [math.PR]

  42. [42]

    Construction ofR-matrices for symmetric tensor representations related toUq(ˆsln),

    G. Bosnjak and V. V. Mangazeev, “Construction ofR-matrices for symmetric tensor representations related toUq(ˆsln),” J. Phys. A49no. 49, (2016) 495204,arXiv:1607.07968 [math-ph]

  43. [43]

    Rational R-matrices in irreducible representations,

    N. J. MacKay, “Rational R-matrices in irreducible representations,”J. Phys. A24no. 17, (1991) 4017

  44. [44]

    Factorization of the R-matrix. I.,

    S. E. Derkachov, “Factorization of the R-matrix. I.,”J. Math. Sci. no. 143, (2007) 2773–2790, arXiv:math/0503396 [math.QA]

  45. [45]

    Bošnjak,On solutions to the Yang–Baxter equation related tosl(n)

    G. Bošnjak,On solutions to the Yang–Baxter equation related tosl(n). PhD thesis, Australian National University, 2017.arXiv:1412.3339 [hep-th]

  46. [46]

    R-matrix and Baxter Q-operators for the noncompact SL(N,C) invariant spin chain,

    S. E. Derkachov and A. N. Manashov, “R-matrix and Baxter Q-operators for the noncompact SL(N,C) invariant spin chain,”SIGMA2(2006) 084,arXiv:nlin/0612003 [nlin.SI]. 60

  47. [47]

    On diagonal solutions of the reflection equation,

    Z. Tsuboi, “On diagonal solutions of the reflection equation,”J. Phys. A52no. 15, (2019) 155201, arXiv:1811.10407 [math-ph]

  48. [48]

    Reflection operator and hypergeometry I: SL(2,R) spin chain,

    P. V. Antonenko, N. M. Belousov, S. E. Derkachov, and S. M. Khoroshkin, “Reflection operator and hypergeometry I: SL(2,R) spin chain,”Zap. Nauchn. Semin.532(2024) 5–46, arXiv:2406.19862 [math-ph]

  49. [49]

    Intertwining and propagation of mixtures for generalized KMP models and harmonic models,

    C. Giardinà, F. Redig, and B. van Tol, “Intertwining and propagation of mixtures for generalized KMP models and harmonic models,”J. Stat. Phys.192no. 2, (2025) 21,arXiv:2406.01160 [math.PR]

  50. [50]

    Hidden Temperature in the KMP Model,

    A. de Masi, P. A. Ferrari, and D. Gabrielli, “Hidden Temperature in the KMP Model,”J. Stat. Phys.191no. 11, (2024) 150,arXiv:2310.01672 [math.PR]

  51. [51]

    Asymptotic behavior of multicolor QCD at high energies in connection with exactly solvable spin models,

    L. N. Lipatov, “Asymptotic behavior of multicolor QCD at high energies in connection with exactly solvable spin models,”JETP Lett.59(1994) 596–599,arXiv:hep-th/9311037

  52. [52]

    High-energy QCD as a completely integrable model,

    L. D. Faddeev and G. P. Korchemsky, “High-energy QCD as a completely integrable model,”Phys. Lett. B342(1995) 311–322,arXiv:hep-th/9404173

  53. [53]

    Baryon distribution amplitudes in QCD,

    V. M. Braun, S. E. Derkachov, G. P. Korchemsky, and A. N. Manashov, “Baryon distribution amplitudes in QCD,”Nucl. Phys. B553(1999) 355–426,arXiv:hep-ph/9902375

  54. [54]

    Integrable heat conduction model,

    C. Franceschini, R. Frassek, and C. Giardinà, “Integrable heat conduction model,”J. Math. Phys. 64no. 4, (2023) 043304,arXiv:2210.13627 [cond-mat.stat-mech]

  55. [55]

    Baxter’s Q-operator for the homogeneous XXX spin chain,

    S. E. Derkachov, “Baxter’s Q-operator for the homogeneous XXX spin chain,”J. Phys. A32(1999) 5299–5316,arXiv:solv-int/9902015

  56. [56]

    Factorization of R-matrix and Baxter Q-operators for generic sl(N) spin chains,

    S. E. Derkachov and A. N. Manashov, “Factorization of R-matrix and Baxter Q-operators for generic sl(N) spin chains,”J. Phys. A42(2009) 075204,arXiv:0809.2050 [nlin.SI]

  57. [57]

    Yangians and their applications,

    A. I. Molev, “Yangians and their applications,” inHandbook of Algebra, vol. 3, pp. 907–959. Elsevier, 2003

  58. [58]

    A New Generalisation of Macdonald Polynomials,

    A. Garbali, J. de Gier, and M. Wheeler, “A New Generalisation of Macdonald Polynomials,” Commun. Math. Phys.352no. 2, (2017) 773–804,arXiv:1605.07200 [math-ph]

  59. [59]

    Macdonald processes,

    A. Borodin and I. Corwin, “Macdonald processes,”Probab. Theory Rel. Fields158no. 1-2, (2014) 225–400,arXiv:1111.4408 [math.PR]

  60. [60]

    J. E. Humphreys,Introduction to Lie Algebras and Representation Theory, vol. 9 ofGraduate Texts in Mathematics. Springer-Verlag, New York, 1972

  61. [61]

    Sulle funzioni ipergeometriche a più variabili,

    G. Lauricella, “Sulle funzioni ipergeometriche a più variabili,”Rend. Circ. Mat. Palermo7 no. Suppl 1, (1893) 111–158

  62. [62]

    Neumann expansions for a certain class of generalised multiple hypergeometric series arising in physical and quantum chemical applications,

    H. M. Srivastava, “Neumann expansions for a certain class of generalised multiple hypergeometric series arising in physical and quantum chemical applications,”J. Phys. A20no. 4, (1987) 847–858

  63. [63]

    Nested Bethe ansatz for y(gl(n)) open spin chains with diagonal boundary conditions,

    S. Belliard and E. Ragoucy, “Nested Bethe ansatz for y(gl(n)) open spin chains with diagonal boundary conditions,”Phys. Part. Nucl. Lett.8(2011) 218–227,arXiv:1001.1314 [math-ph]

  64. [64]

    Matrix product solution to the reflection equation associated with a coideal subalgebra ofUq(A(1) n−1),

    A. Kuniba, M. Okado, and A. Yoneyama, “Matrix product solution to the reflection equation associated with a coideal subalgebra ofUq(A(1) n−1),” Lett. Math. Phys.109no. 9, (2019) 2049–2067, arXiv:1812.03767 [math-ph]. 61

  65. [65]

    Exact solution of an integrable non-equilibrium particle system,

    R. Frassek and C. Giardinà, “Exact solution of an integrable non-equilibrium particle system,”J. Math. Phys.63no. 10, (2022) 103301,arXiv:2107.01720 [math-ph]

  66. [66]

    Eigenstates of triangularisable open XXX spin chains and closed-form solutions for the steady state of the open SSEP,

    R. Frassek, “Eigenstates of triangularisable open XXX spin chains and closed-form solutions for the steady state of the open SSEP,”J. Stat. Mech.2005(2020) 053104,arXiv:1910.13163 [math-ph]

  67. [67]

    Duality and hidden equilibrium in transport models,

    R. Frassek, C. Giardina, and J. Kurchan, “Duality and hidden equilibrium in transport models,” SciPost Phys.9(2020) 054,arXiv:2004.12796 [cond-mat.stat-mech]

  68. [68]

    work in progress,

    R. Frassek, C. Giardinà, F. Redig, and B. van Tol, “work in progress,”. 62