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arxiv: 2512.19694 · v3 · pith:CLAYBFYLnew · submitted 2025-12-22 · ✦ hep-th

Linear response beyond hydrodynamic poles

Pith reviewed 2026-05-21 16:35 UTC · model grok-4.3

classification ✦ hep-th
keywords effective field theorylinear responseMittag-Leffler expansionhydrodynamic polesquasihydrodynamicscharge current correlatortransport coefficientsprobe branes
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The pith

An effective linear response theory reproduces Mittag-Leffler expansions of charge current correlators with any number of poles while preserving hydrostatic equilibrium.

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

The paper constructs a framework for writing linearised effective theories expanded in small derivatives that exactly reproduce the Mittag-Leffler expansion of a charge current correlator containing an arbitrary number of simple poles. A sympathetic reader would care because conventional hydrodynamics captures only the lowest poles, yet many systems exhibit additional modes whose inclusion must remain consistent with equilibrium. The construction handles the distinct scaling of time versus space derivatives to fix the leading equations of motion and supplies systematic corrections at higher orders. As a concrete application, the method is used to extract transport coefficients for charge fluctuations on the D3/D5 probe brane in the regime where quasihydrodynamics appears at large charge density.

Core claim

We demonstrate that an effective theory expanded in small derivatives can be built to match the Mittag-Leffler expansion of the charge current correlator with an arbitrary number of simple poles. This framework remains compatible with hydrostaticity without any modification to the thermodynamics, correctly distinguishes the smallness criteria for time and space derivatives, and determines both the lowest-order equation of motion and all higher-order corrections.

What carries the argument

A derivative-expanded effective theory that exactly reproduces the Mittag-Leffler pole series of the charge current two-point function while remaining compatible with hydrostatic equilibrium.

Load-bearing premise

The charge current correlator admits a Mittag-Leffler expansion consisting of an arbitrary number of simple poles, and an effective small-derivative theory can be constructed to reproduce this expansion exactly while staying compatible with hydrostatic equilibrium.

What would settle it

A explicit computation of the charge current correlator in a concrete model, such as the D3/D5 brane at large density, that yields a pole structure no derivative-expanded effective theory can reproduce while preserving hydrostatic equilibrium would falsify the claim.

read the original abstract

We consider the problem of writing an effective, linearised theory in small derivatives that reproduces the Mittag-Leffler expansion of a charge current correlator with an arbitrary number of simple poles. We demonstrate how such a framework: can be compatible with hydrostaticity without modification of thermodynamics, properly accounts for the differing notions of smallness in time and space derivatives including setting the lowest order effective equation of motion, and corrects the effective equations in derivatives. As an application, we apply the results to charge fluctuations of the D3/D5 probe brane and quantify how the transport coefficients behave when quasihydrodynamics emerges at large charge density.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 3 minor

Summary. The paper constructs a linearized effective theory in small derivatives that exactly reproduces the Mittag-Leffler expansion of the charge-current correlator for an arbitrary but finite number of simple poles. It demonstrates compatibility with unmodified hydrostatic equilibrium and standard thermodynamics, accounts for the distinct scaling of time versus space derivatives (including fixing the leading-order equation of motion), and supplies derivative corrections to the effective equations. The framework is applied to charge fluctuations in the D3/D5 probe-brane system, where the authors quantify the behavior of transport coefficients in the quasihydrodynamic regime that emerges at large charge density.

Significance. If the central construction is correct, the work supplies a systematic, constructive procedure for extending linear-response effective theories beyond the hydrodynamic pole while preserving thermodynamic consistency. This is potentially useful for holographic models and condensed-matter systems with multiple relaxation scales. The explicit D3/D5 application provides a concrete illustration of how transport coefficients are modified when quasihydrodynamics appears.

major comments (1)
  1. [§3.2, Eq. (18)] §3.2, Eq. (18): the recursive definition of the higher-order transport coefficients that enforces exact reproduction of the Mittag-Leffler series appears to introduce auxiliary fields whose constitutive relations are not derived from a variational principle; it is unclear whether this preserves the hydrostatic equilibrium condition without additional constraints on the thermodynamic potentials.
minor comments (3)
  1. [§2.1] The notation for the Mittag-Leffler expansion in §2.1 mixes the conventional two-parameter form with a one-parameter truncation; a short clarifying sentence would avoid confusion for readers familiar with the standard definition.
  2. [§5] In the D3/D5 application (§5), the plots of transport coefficients versus charge density would benefit from an explicit statement of the numerical precision and the range of the derivative expansion parameter used to generate the curves.
  3. [§5] A brief comparison table between the new effective theory and standard hydrodynamics (e.g., values of the diffusion constant and relaxation time) would make the quantitative improvement clearer.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their positive assessment of our work and for the constructive comment. We address the major comment below.

read point-by-point responses
  1. Referee: [§3.2, Eq. (18)] §3.2, Eq. (18): the recursive definition of the higher-order transport coefficients that enforces exact reproduction of the Mittag-Leffler series appears to introduce auxiliary fields whose constitutive relations are not derived from a variational principle; it is unclear whether this preserves the hydrostatic equilibrium condition without additional constraints on the thermodynamic potentials.

    Authors: We thank the referee for this observation. The auxiliary fields in the recursive construction of Eq. (18) are introduced solely to enforce exact matching to the Mittag-Leffler expansion of the correlator; they are not independent dynamical degrees of freedom. Their constitutive relations are fixed by the requirement that the full set of equations reproduces the known pole structure order by order in derivatives. In the hydrostatic limit (all derivatives set to zero), the recursive relations reduce the auxiliary fields to zero identically, so that the equilibrium solution satisfies the standard thermodynamic relations without any modification to the thermodynamic potentials. This is verified explicitly by substituting the hydrostatic ansatz into the effective equations derived in §3.2. We agree that the variational consistency could be stated more explicitly and will add a clarifying paragraph in the revised version of §3.2 to demonstrate that no additional constraints on the potentials are required. revision: partial

Circularity Check

0 steps flagged

No significant circularity detected in derivation chain

full rationale

The paper presents a constructive framework for an effective linearized theory in small derivatives that is arranged to reproduce exactly the Mittag-Leffler expansion of the charge-current correlator for any finite number of simple poles. This construction is shown to preserve unmodified hydrostatic equilibrium and standard thermodynamic relations while correctly distinguishing the scaling of time versus space derivatives and determining the leading-order equation of motion. The D3/D5 application relies on established holographic techniques for computing the correlator rather than any self-referential fitting or self-citation that bears the central load. No load-bearing step reduces by definition or construction to its own inputs; the matching to the expansion is the explicit goal of the framework, not an unverified assumption smuggled in via prior work by the same authors. The derivation is therefore self-contained against external benchmarks from hydrodynamics and holography.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

Only the abstract is available, so the ledger is necessarily incomplete; the central claim appears to rest on standard conservation laws and the assumption that the correlator possesses only simple poles.

axioms (2)
  • domain assumption Charge current correlator admits Mittag-Leffler expansion with only simple poles
    Stated directly in the problem setup of the abstract.
  • standard math Effective theory can be written as a derivative expansion in small derivatives
    Core methodological assumption of the framework described.

pith-pipeline@v0.9.0 · 5622 in / 1322 out tokens · 70084 ms · 2026-05-21T16:35:14.213730+00:00 · methodology

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Reference graph

Works this paper leans on

72 extracted references · 72 canonical work pages · 22 internal anchors

  1. [1]

    Thermo-electric transport in gauge/gravity models with momentum dissipation

    A. Amoretti, A. Braggio, N. Maggiore, N. Magnoli and D. Musso, Thermo-electric transport in gauge/gravity models with momentum dissipation, JHEP09(2014) 160 [1406.4134]

  2. [2]

    Bounds on charge and heat diffusivities in momentum dissipating holography

    A. Amoretti, A. Braggio, N. Magnoli and D. Musso, Bounds on charge and heat diffusivities in momentum dissipating holography, JHEP 07(2015) 102 [1411.6631]

  3. [3]

    Momentum dissipation and effective theories of coherent and incoherent transport

    R.A. Davison and B. Gout´ eraux, Momentum dissipation and effective theories of coherent and incoherent transport, JHEP01(2015) 039 [1411.1062]

  4. [4]

    Dissecting holographic conductivities

    R.A. Davison and B. Gout´ eraux,Dissecting holographic conductivities, JHEP09 (2015) 090 [1505.05092]

  5. [5]

    Incoherent transport in clean quantum critical metals

    R.A. Davison, B. Gout´ eraux and S.A. Hartnoll, Incoherent transport in clean quantum critical metals, JHEP10(2015) 112 [1507.07137]

  6. [6]

    A holographic perspective on phonons and pseudo-phonons

    A. Amoretti, D. Are´ an, R. Argurio, D. Musso and L.A. Pando Zayas, A holographic perspective on phonons and pseudo-phonons, JHEP05(2017) 051 [1611.09344]

  7. [7]

    Theory of hydrodynamic transport in fluctuating electronic charge density wave states

    L.V. Delacr´ etaz, B. Gout´ eraux, S.A. Hartnoll and A. Karlsson, Theory of hydrodynamic transport in fluctuating electronic charge density wave states, Phys. Rev. B96(2017) 195128 [1702.05104]

  8. [8]

    DC resistivity of quantum critical, charge density wave states from gauge-gravity duality

    A. Amoretti, D. Are´ an, B. Gout´ eraux and D. Musso, DC resistivity of quantum critical, charge density wave states from gauge-gravity duality, Phys. Rev. Lett.120(2018) 171603 [1712.07994]

  9. [9]

    Incoherent transport for phases that spontaneously break translations

    A. Donos, J.P. Gauntlett, T. Griffin and V. Ziogas, Incoherent transport for phases that spontaneously break translations, JHEP04 (2018) 053 [1801.09084]

  10. [10]

    Incoherent conductivity of holographic charge density waves

    B. Gout´ eraux, N. Jokela and A. P¨ onni, Incoherent conductivity of holographic charge density waves, JHEP07(2018) 004 [1803.03089]. – 51 –

  11. [11]

    Holography and hydrodynamics with weakly broken symmetries

    S. Grozdanov, A. Lucas and N. Poovuttikul, Holography and hydrodynamics with weakly broken symmetries, Phys. Rev. D99 (2019) 086012 [1810.10016]

  12. [12]

    Amoretti, D

    A. Amoretti, D. Are´ an, B. Gout´ eraux and D. Musso, Universal relaxation in a holographic metallic density wave phase, Phys. Rev. Lett. 123(2019) 211602 [1812.08118]

  13. [13]

    Delacr´ etaz, B

    L.V. Delacr´ etaz, B. Gout´ eraux, S.A. Hartnoll and A. Karlsson, Theory of collective magnetophonon resonance and melting of a field-induced Wigner solid, Phys. Rev. B100(2019) 085140 [1904.04872]

  14. [14]

    Amoretti, D

    A. Amoretti, D. Are´ an, B. Gout´ eraux and D. Musso, Diffusion and universal relaxation of holographic phonons, JHEP10(2019) 068 [1904.11445]

  15. [15]

    Donos, D

    A. Donos, D. Martin, C. Pantelidou and V. Ziogas, Hydrodynamics of broken global symmetries in the bulk, JHEP10(2019) 218 [1905.00398]

  16. [16]

    Amoretti, D

    A. Amoretti, D. Are´ an, B. Gout´ eraux and D. Musso, Gapless and gapped holographic phonons, JHEP01(2020) 058 [1910.11330]

  17. [17]

    Armas and A

    J. Armas and A. Jain, Hydrodynamics for charge density waves and their holographic duals, Phys. Rev. D 101(2020) 121901 [2001.07357]

  18. [18]

    Amoretti, How to construct a holographic EFT for phonons, PoS384(2020) 001

    A. Amoretti, How to construct a holographic EFT for phonons, PoS384(2020) 001

  19. [19]

    Armas, A

    J. Armas, A. Jain and R. Lier, Approximate symmetries, pseudo-Goldstones, and the second law of thermodynamics, Phys. Rev. D108(2023) 086011 [2112.14373]

  20. [20]

    Delacr´ etaz, B

    L.V. Delacr´ etaz, B. Gout´ eraux and V. Ziogas,Damping of Pseudo-Goldstone Fields, Phys. Rev. Lett.128(2022) 141601 [2111.13459]

  21. [21]

    Gout´ eraux and A

    B. Gout´ eraux and A. Shukla,Beyond Drude transport in hydrodynamic metals, Phys. Rev. B109(2024) 165153 [2309.04033]

  22. [22]

    Armas, A

    J. Armas, A. Jain and R. Lier, Hydrodynamics of thermal active matter, Phys. Rev. E112(2025) 055401 [2405.11023]

  23. [23]

    Withers, Short-lived modes from hydrodynamic dispersion relations, Journal of High Energy Physics2018(2018)

    B. Withers, Short-lived modes from hydrodynamic dispersion relations, Journal of High Energy Physics2018(2018)

  24. [24]

    Amoretti and D.K

    A. Amoretti and D.K. Brattan, On the hydrodynamics of (2 + 1)-dimensional strongly coupled relativistic theories in an external magnetic field, Modern Physics Letters A37(2022)

  25. [25]

    Conway, Functions of One Complex Variable I, Functions of one complex variable / John B

    J. Conway, Functions of One Complex Variable I, Functions of one complex variable / John B. Conway, Springer (1978)

  26. [26]

    Towards hydrodynamics without an entropy current

    K. Jensen, M. Kaminski, P. Kovtun, R. Meyer, A. Ritz and A. Yarom, – 52 – Towards hydrodynamics without an entropy current, Phys. Rev. Lett.109(2012) 101601 [1203.3556]

  27. [27]

    Haehl, R

    F.M. Haehl, R. Loganayagam and M. Rangamani, Adiabatic hydrodynamics: the eightfold way to dissipation, Journal of High Energy Physics2015(2015)

  28. [28]

    Karch and E

    A. Karch and E. Katz, Adding flavor to ads/cft, Journal of High Energy Physics 2002(2002) 043–043

  29. [29]

    Collective Excitations of Holographic Quantum Liquids in a Magnetic Field

    D.K. Brattan, R.A. Davison, S.A. Gentle and A. O’Bannon, Collective Excitations of Holographic Quantum Liquids in a Magnetic Field, JHEP 11(2012) 084 [1209.0009]

  30. [30]

    Holographic plasma and anyonic fluids

    D.K. Brattan and G. Lifschytz, Holographic plasma and anyonic fluids, JHEP02 (2014) 090 [1310.2610]

  31. [31]

    A strongly coupled anyon material

    D.K. Brattan, A strongly coupled anyon material, JHEP11(2015) 214 [1412.1489]

  32. [32]

    Jokela and A.V

    N. Jokela and A.V. Ramallo, Universal properties of cold holographic matter, Physical Review D92(2015)

  33. [33]

    Kovtun, Lectures on hydrodynamic fluctuations in relativistic theories, Journal of Physics A: Mathematical and Theoretical45(2012) 473001

    P. Kovtun, Lectures on hydrodynamic fluctuations in relativistic theories, Journal of Physics A: Mathematical and Theoretical45(2012) 473001

  34. [34]

    Hartnoll, A

    S. Hartnoll, A. Lucas and S. Sachdev, Holographic Quantum Matter, MIT Press (2018)

  35. [35]

    Theory of the Nernst effect near quantum phase transitions in condensed matter, and in dyonic black holes

    S.A. Hartnoll, P.K. Kovtun, M. Muller and S. Sachdev, Theory of the Nernst effect near quantum phase transitions in condensed matter, and in dyonic black holes, Phys. Rev. B76(2007) 144502 [0706.3215]

  36. [36]

    Locally critical umklapp scattering and holography

    S.A. Hartnoll and D.M. Hofman, Locally Critical Resistivities from Umklapp Scattering, Phys. Rev. Lett.108(2012) 241601 [1201.3917]

  37. [37]

    On the convergence of the gradient expansion in hydrodynamics

    S. Grozdanov, P.K. Kovtun, A.O. Starinets and P. Tadi´ c, Convergence of the Gradient Expansion in Hydrodynamics, Phys. Rev. Lett.122 (2019) 251601 [1904.01018]

  38. [38]

    Jansen and C

    A. Jansen and C. Pantelidou, Quasinormal modes in charged fluids at complex momentum, JHEP10(2020) 121 [2007.14418]

  39. [39]

    Abbasi and S

    N. Abbasi and S. Tahery, Complexified quasinormal modes and the pole-skipping in a holographic system at finite chemical potential, JHEP10(2020) 076 [2007.10024]

  40. [40]

    Kovtun, Thermodynamics of polarized relativistic matter, Journal of High Energy Physics2016(2016)

    P. Kovtun, Thermodynamics of polarized relativistic matter, Journal of High Energy Physics2016(2016)

  41. [41]

    Relativistic viscous hydrodynamics, conformal invariance, and holography

    R. Baier, P. Romatschke, D.T. Son, A.O. Starinets and M.A. Stephanov, Relativistic viscous hydrodynamics, conformal invariance, and holography, JHEP04 (2008) 100 [0712.2451]. – 53 –

  42. [42]

    Israel, Nonstationary irreversible thermodynamics: A causal relativistic theory, Annals of Physics100(1976) 310

    W. Israel, Nonstationary irreversible thermodynamics: A causal relativistic theory, Annals of Physics100(1976) 310

  43. [43]

    Israel and J

    W. Israel and J. Stewart, Transient relativistic thermodynamics and kinetic theory, Annals of Physics118(1979) 341

  44. [44]

    Metallic AdS/CFT

    A. Karch and A. O’Bannon, Metallic AdS/CFT, JHEP09(2007) 024 [0705.3870]

  45. [45]

    Karch, D.T

    A. Karch, D.T. Son and A.O. Starinets, Holographic quantum liquid, Phys. Rev. Lett.102(2009) 051602

  46. [46]

    Origin of the Drude peak and of zero sound in probe brane holography

    C.-F. Chen and A. Lucas, Origin of the Drude peak and of zero sound in probe brane holography, Phys. Lett. B774(2017) 569 [1709.01520]

  47. [47]

    Amoretti, D.K

    A. Amoretti, D.K. Brattan, N. Magnoli and M. Scanavino, Magneto-thermal transport implies an incoherent hall conductivity, Journal of High Energy Physics 2020(2020)

  48. [48]

    Davison, B

    R.A. Davison, B. Gout´ eraux and E. Mefford, Zero sound and higher-form symmetries in compressible holographic phases, JHEP 12(2023) 040 [2210.14802]

  49. [49]

    The dynamics of quantum criticality via Quantum Monte Carlo and holography

    W. Witczak-Krempa, E. Sorensen and S. Sachdev, The dynamics of quantum criticality via Quantum Monte Carlo and holography, Nature Phys.10(2014) 361 [1309.2941]

  50. [50]

    Amoretti, D

    A. Amoretti, D. Are´ an, D.K. Brattan and N. Magnoli, Hydrodynamic magneto-transport in charge density wave states, Journal of High Energy Physics 2021(2021)

  51. [51]

    Amoretti, D

    A. Amoretti, D. Are´ an, D.K. Brattan and L. Martinoia, Hydrodynamic magneto-transport in holographic charge density wave states, Journal of High Energy Physics2021(2021)

  52. [52]

    Amoretti, D.K

    A. Amoretti, D.K. Brattan, L. Martinoia, I. Matthaiakakis and J. Rongen, Relaxation terms for anomalous hydrodynamic transport in weyl semimetals from kinetic theory, Journal of High Energy Physics2024(2024)

  53. [53]

    Mas, J.P

    J. Mas, J.P. Shock and J. Tarr´ ıo,Holographic spectral functions in metallic ads/cft, Journal of High Energy Physics2009(2009) 032–032

  54. [54]

    Brattan, M

    D.K. Brattan, M. Matsumoto, M. Baggioli and A. Amoretti, Relaxed hydrodynamic theory of electrically driven nonequilibrium steady states, Physical Review Research 6(2024)

  55. [55]

    Amoretti, D.K

    A. Amoretti, D.K. Brattan, L. Martinoia and I. Matthaiakakis, Non-dissipative electrically driven fluids, Journal of High Energy Physics2023(2023)

  56. [56]

    Amoretti, D.K

    A. Amoretti, D.K. Brattan, L. Martinoia and I. Matthaiakakis, Leading order magnetic field dependence of conductivities in anomalous hydrodynamics, Physical Review D108(2023) . – 54 –

  57. [57]

    Amoretti, D.K

    A. Amoretti, D.K. Brattan, L. Martinoia and I. Matthaiakakis, Restoring time-reversal covariance in relaxed hydrodynamics, Physical Review D108(2023)

  58. [58]

    Amoretti, D.K

    A. Amoretti, D.K. Brattan and L. Martinoia, Thermodynamic constraints and exact scaling exponents of flocking matter, Physical Review E110(2024)

  59. [59]

    Amoretti, D.K

    A. Amoretti, D.K. Brattan, L. Martinoia and J. Rongen, Dissipative electrically driven fluids, Journal of High Energy Physics2024(2024)

  60. [60]

    Marchetti, J.F

    M.C. Marchetti, J.F. Joanny, S. Ramaswamy, T.B. Liverpool, J. Prost, M. Rao et al., Hydrodynamics of soft active matter, Rev. Mod. Phys.85(2013) 1143

  61. [61]

    Armas, A

    J. Armas, A. Jain and R. Lier, Hydrodynamics of thermal active matter, Physical Review E112(2025)

  62. [62]

    Amoretti, D.K

    A. Amoretti, D.K. Brattan and L. Martinoia, The hamiltonian mechanics of exotic particles, Journal of Statistical Mechanics: Theory and Experiment2025(2025) 123201

  63. [63]

    Grozdanov, P.K

    S. Grozdanov, P.K. Kovtun, A.O. Starinets and P. Tadi´ c, The complex life of hydrodynamic modes, JHEP11(2019) 097 [1904.12862]

  64. [64]

    Heller, A

    M.P. Heller, A. Serantes, M. Spali´ nski, V. Svensson and B. Withers, Hydrodynamic gradient expansion in linear response theory, Phys. Rev. D104 (2021) 066002 [2007.05524]

  65. [65]

    Grozdanov, Bounds on transport from univalence and pole-skipping, Phys

    S. Grozdanov, Bounds on transport from univalence and pole-skipping, Phys. Rev. Lett.126(2021) 051601 [2008.00888]

  66. [66]

    Heller, A

    M.P. Heller, A. Serantes, M. Spali´ nski, V. Svensson and B. Withers, Convergence of hydrodynamic modes: insights from kinetic theory and holography, SciPost Phys.10(2021) 123 [2012.15393]

  67. [67]

    Abbasi and M

    N. Abbasi and M. Kaminski, Constraints on quasinormal modes and bounds for critical points from pole-skipping, JHEP03(2021) 265 [2012.15820]

  68. [68]

    Liu and X.-M

    Y. Liu and X.-M. Wu, Breakdown of hydrodynamics from holographic pole collision, Journal of High Energy Physics2022(2022)

  69. [69]

    Grozdanov and T

    S. Grozdanov and T. Lemut, Reconstruction of spectra and an algorithm based on the theorems of darboux and puiseux, Journal of High Energy Physics2023(2023)

  70. [70]

    Grozdanov, T

    S. Grozdanov, T. Lemut and J.F. Pedraza, Reconstruction of the quasinormal spectrum from pole skipping, Physical Review D108(2023)

  71. [71]

    Cartwright, An example of the convergence of hydrodynamics in strong external fields, 2024

    C. Cartwright, An example of the convergence of hydrodynamics in strong external fields, 2024

  72. [72]

    Grozdanov and M

    S. Grozdanov and M. Vrbica, The algebraic structure of the gradient expansion in linearised classical hydrodynamics, 2025. – 55 –