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Nonlinear stability of periodic waves in the Korteweg-de Vries equation under localized perturbations

T0 review · 0 major / 4 minor · reviewed 2026-07-10 · grok-4.5

Pith's one-line read Periodic cnoidal waves of the KdV equation are nonlinearly stable under localized perturbations via spatiotemporal modulation.

desk verdict First genuine nonlinear stability theorem for multi-mode periodic waves under localized data in a Hamiltonian system; the method is reusable and the KdV case is cleanly closed. read the letter →

arxiv 2607.08401 v1 pith:6VBCCXFM submitted 2026-07-09 math.AP

classification math.AP MSC 35B1035Q5337K4537K58
keywords Korteweg-deVriesequationcnoidalwavesnonlinearstabilitylocalizedperturbationsspatiotemporalmodulationdiffusivespectralFloquet-BlochtheoryHamiltoniansystems
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

Standard Hamiltonian stability methods fail for periodic waves under localized (non-periodic) perturbations because the second variation of energy is only semi-definite and its spectrum is essential. This paper resolves that obstruction for cnoidal waves of the Korteweg–de Vries equation by introducing a conserved energy whose second variation is diffusively spectrally stable, then tracking the solution with a space–time modulation that absorbs the neutral translational modes. The result is the first nonlinear stability theorem for genuine multi-mode periodic waves in a Hamiltonian system under fully localized perturbations: the solution stays close to a slowly modulated copy of the wave, and orbital stability holds locally in space. The same framework reduces the problem for general Hamiltonian systems with symmetry to a spectral check on the second variation.

What carries the argument

Diffusive spectral stability of the second variation A_γ of a conserved energy (a linear combination of the first two KdV Hamiltonians): this yields a coercivity estimate at the cost of one derivative of the modulation, which is then closed by Duhamel estimates on the inverse-modulated residual.

What would settle it

Either exhibit a cnoidal wave for which every candidate conserved energy has a second variation that is not diffusively spectrally stable, or produce a small H^{3}-localized perturbation that drives the solution away from every space–time modulation of the wave in H^{2}.

Watch

Extended reading notes

Core claim

Cnoidal waves of the KdV equation are nonlinearly modulationally stable under H^{3}-localized perturbations: the solution remains close in H^{2} to a space–time modulated traveling wave, the space–time gradient of the modulation stays small in any Sobolev norm, and local orbital stability holds on every finite interval.

Load-bearing premise

There must exist a conserved energy whose second variation about the wave is diffusively spectrally stable; without that spectral input the coercivity estimate fails and the argument collapses.

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Referee Report

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Summary. The paper proves nonlinear modulational stability of cnoidal waves for the KdV equation under localized (H^3) perturbations. After reducing to a moving frame, the authors construct a relative energy from a linear combination E_\gamma of the first two KdV Hamiltonians, introduce an inverse-modulated perturbation, and obtain a Duhamel formula. Diffusive spectral stability of the second variation A_\gamma (Definition 1.1, Theorem 1.2, verified via squared-eigenfunction bases in Appendix C) yields a coercivity estimate at the cost of a derivative of the modulation (Proposition 2.3 / Corollary 3.8). A template-function bootstrap then closes global smallness of the modulated remainder and of ∇ψ, producing Theorem 1.4 (and its higher-order extension Corollary 4.3): the solution stays close in H^2 to a spatiotemporally modulated cnoidal wave, with local orbital stability on every finite interval. The abstract framework of §1.1 isolates the spectral hypothesis so that the nonlinear argument applies to general Hamiltonian systems with symmetry once an analogous energy is available.

Significance. Nonlinear stability of genuinely multi-mode periodic waves under localized perturbations has been open in Hamiltonian systems since Benjamin’s 1974 lectures; previous results were limited to plane waves reducible to constants by gauge symmetry. The paper supplies the first such theorem for cnoidal waves of KdV and, more importantly, a clean reduction of the problem to a verifiable spectral condition on a conserved energy. The proof chain (well-posedness, relative-energy conservation, inverse modulation, Floquet–Bloch coercivity, Duhamel residual control, template bootstrap) is complete and self-contained. The isolation of the spectral input, the higher-order extension via the KdV hierarchy, and the explicit discussion of extensions (multiple symmetries, Whitham dynamics, indefinite energies) make the work a substantial advance that is likely to be used beyond KdV.

minor comments (4)
  1. The linear growth bound ||φ(t)||_L^{2} ː (1+t) in (1.22) is conjectured in §1.2 to be improvable to (1+t)^{1/2}; a short remark quantifying the expected sharpness (or the obstruction to proving it with the present energy) would help readers.
  2. Figure 2 is informative but the caption could state more explicitly that the initial data are constructed so that the net phase shift vanishes, making the expanding plateaus a pure phase-defect phenomenon.
  3. In Appendix C the interval I for γ is given as (4(3E-2),4(4E-2)); a one-line numerical illustration for a typical elliptic modulus (e.g., E=0.5) would make the range concrete.
  4. A few typographical inconsistencies appear (e.g., “Björn” vs. “BJ ÖRN” in the header, occasional missing spaces around operators). A light copy-edit pass would remove them.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity; the nonlinear claim reduces cleanly to an independently verified spectral hypothesis on a conserved energy, with only minor non-load-bearing self-citations.

full rationale

The derivation chain of Theorem 1.4 is a standard variational + modulation + Duhamel bootstrap that takes as black-box input the existence of a conserved energy E_γ whose second variation A_γ is diffusively spectrally stable (Definition 1.1). That spectral input is established independently in Theorem 1.2 / Appendix C by representing A_γ(ξ) on the Riesz bases of Bloch eigenfunctions of the linearization L(ξ) furnished by the squared-eigenfunction connection of the Lax pair (citing external works [14,69] and the commuting-flow property of the KdV hierarchy). Once the coercivity estimate of Proposition 2.3 is available, the remainder of the argument (inverse modulation of the relative energy, choice of modulation via the spectral projection of A_γ, residual estimates via Duhamel, and the template-function bootstrap in §4) follows by direct estimates and does not feed back into the spectral hypothesis. Self-citations (e.g., to the authors’ prior plane-wave result [16]) appear only as illustrative examples of the general framework and are not used to justify any load-bearing step for the KdV cnoidal waves. No quantity is fitted, no uniqueness theorem is imported from the authors’ own prior work to force the conclusion, and no ansatz is smuggled in; the reduction is therefore non-circular.

Assumptions & free parameters 0 free parameters · 4 assumptions · 0 invented entities

The central claim rests on standard functional-analytic tools (Floquet-Bloch, C0-groups, elliptic regularity) plus one domain-specific spectral hypothesis that is verified for KdV by integrability. No free parameters are fitted; the interval I for the energy parameter γ is shown to be nonempty by explicit computation. No new physical entities are postulated.

assumptions (4)
  • standard math Floquet-Bloch spectral decomposition of periodic-coefficient operators on L2(R) (relation (1.6))
    Used throughout §§1–2 and Appendix A; classical.
  • domain assumption Existence of a conserved energy E_γ whose second variation is diffusively spectrally stable (Definition 1.1, Theorem 1.2)
    The entire nonlinear argument reduces to this input; verified for KdV via Lax-pair eigenfunctions but postulated for the general framework.
  • standard math Global well-posedness of the KdV perturbation equation in H^{m+3} (Proposition 3.1)
    Taken from the energy-method literature (Bona-Smith, Erdoğan-Tzirakis); used as black box.
  • domain assumption Riesz-basis property of the squared eigenfunctions of the linearized KdV operator (Proposition C.1)
    Cited from Bottman-Deconinck and Rodrigues; essential for the spectral verification in Appendix C.

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Pith. "Pith review of Nonlinear stability of periodic waves in the Korteweg-de Vries equation under localized perturbations." pith.science (2026). https://pith.science/paper/6VBCCXFM

@misc{pith2026260708401,
  author       = {Pith},
  title        = {Pith review of: Nonlinear stability of periodic waves in the Korteweg-de Vries equation under localized perturbations},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/6VBCCXFM}},
  note         = {Machine review of arXiv:2607.08401}
}
read the original abstract

We investigate the stability and asymptotic behavior of spatially periodic cnoidal waves in the Korteweg-de Vries equation subject to localized perturbations. Standard stability arguments in Hamiltonian systems break down in this setting, since localized perturbations preclude a characterization of stable periodic waves as strict minimizers of a suitable energy functional subject to finitely many constraints. As a result, the nonlinear stability of periodic waves under localized perturbations has remained a long-standing open problem in Hamiltonian systems, with previous results only addressing plane waves that can be reduced to constant states by passing to polar coordinates. In this paper, we develop a novel method that resolves this obstruction by combining variational arguments, Floquet-Bloch theory, and Duhamel-based estimates with spatiotemporal modulation. Our framework applies to general periodic waves in Hamiltonian systems with symmetry and reduces the nonlinear stability problem to verifying diffusive spectral stability conditions for the second variation of a suitable conserved energy. Applying our approach to cnoidal waves in the Korteweg-de Vries equation, we obtain the first nonlinear stability result for periodic waves in Hamiltonian systems under localized perturbations that cannot be reduced to constant states.

Figures

Figures reproduced from arXiv: 2607.08401 by the authors.

Figure 1
Figure 1. Left: L 2 (R)-spectrum of an operator A, where −A is diffusively spectrally stable in the sense of Definition 1.1. Right: the L 2 per(0, ℓ)-spectrum of the corresponding Bloch operator A(ξ) for some fixed ξ ∈ [− π ℓ , π ℓ ). Assuming that −A is diffusively spectrally stable, the simple eigenvalue 0 of A(0) can be locally continued in ξ using standard perturbation theory [46], resulting in an eigenvalue λc(ξ) of A(ξ)… view at source ↗
Figure 2
Figure 2. Time integration of a periodic cnoidal wave subject to a localized perturbation. The initial condition is constructed by patching together two exact one-soliton solutions on a cnoidal background from [33], chosen so that the net phase shift of the background is zero. Top: The solution u(t) to (1.12) is shown in blue at t = 0, 4, and 8; the unperturbed cnoidal wave w(x) = 12E cn2 (x − x0, E) with elliptic modulus E =… view at source ↗

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Works this paper leans on

81 extracted references · 81 canonical work pages

  1. [1]

    M. J. Ablowitz and H. Segur.Solitons and the inverse scattering transform. Vol. 4. SIAM Studies in Applied Mathematics. Society for Industrial and Applied Mathematics (SIAM), Philadelphia, PA, 1981, pp. x+425

  2. [2]

    Domain walls in the coupled Gross-Pitaevskii equations

    S. Alama, L. Bronsard, A. Contreras, and D. E. Pelinovsky. “Domain walls in the coupled Gross-Pitaevskii equations”. In:Arch. Ration. Mech. Anal.215.2 (2015), pp. 579–610.doi:10.1007/s00205-014-0789-y

  3. [3]

    Orbital stability of the black soliton for the quintic Gross-Pitaevskii equation

    M. ´A. Alejo and A. J. Corcho. “Orbital stability of the black soliton for the quintic Gross-Pitaevskii equation”. In:Rev. Mat. Iberoam.40.5 (2024), pp. 1731–1780.doi:10.4171/rmi/1467

  4. [4]

    Nonlinear dynamics of reaction-diffusion wave trains under large and fully nonlocalized modulations

    J. Alexopoulos and B. de Rijk. “Nonlinear dynamics of reaction-diffusion wave trains under large and fully nonlocalized modulations”. In:preprint arXiv:2508.08637(2025)

  5. [5]

    Nonlinear stability of periodic traveling wave solutions to the Schr¨ odinger and the modified Korteweg-de Vries equations

    J. Angulo Pava. “Nonlinear stability of periodic traveling wave solutions to the Schr¨ odinger and the modified Korteweg-de Vries equations”. In:J. Differential Equations235.1 (2007), pp. 1–30.doi: 10.1016/j.jde. 2007.01.003. 39

  6. [6]

    Stability of cnoidal waves

    J. Angulo Pava, J. L. Bona, and M. Scialom. “Stability of cnoidal waves”. In:Adv. Differential Equations 11.12 (2006), pp. 1321–1374

  7. [7]

    Positivity properties of the Fourier transform and the stability of periodic travelling-wave solutions

    J. Angulo Pava and F. M. A. Natali. “Positivity properties of the Fourier transform and the stability of periodic travelling-wave solutions”. In:SIAM J. Math. Anal.40.3 (2008), pp. 1123–1151.doi:10.1137/080718450

  8. [8]

    Lectures on nonlinear wave motion

    T. B. Benjamin. “Lectures on nonlinear wave motion”. In:Nonlinear wave motion (Proc. AMS-SIAM Summer Sem., Clarkson Coll. Tech., Potsdam, N.Y., 1972). Lectures in Appl. Math., Vol. 15. Amer. Math. Soc., Providence, RI, 1974, pp. 3–47

Show all 81 references
  1. [9]

    Co-periodic stability of periodic waves in some Hamiltonian PDEs

    S. Benzoni-Gavage, C. Mietka, and L. M. Rodrigues. “Co-periodic stability of periodic waves in some Hamiltonian PDEs”. In:Nonlinearity29.11 (2016), pp. 3241–3308.doi:10.1088/0951-7715/29/11/3241

  2. [10]

    Stability of periodic waves in Hamiltonian PDEs

    S. Benzoni-Gavage, P. Noble, and L. M. Rodrigues. “Stability of periodic waves in Hamiltonian PDEs”. en. In: Journ´ ees ´ equations aux d´ eriv´ ees partielles. Groupement de recherche 2434 du CNRS, 2013, 2, pp. 1–22. doi:10.5802/jedp.98

  3. [11]

    Orbital stability of the black soliton for the Gross- Pitaevskii equation

    F. B´ ethuel, P. Gravejat, J.-C. Saut, and D. Smets. “Orbital stability of the black soliton for the Gross- Pitaevskii equation”. In:Indiana Univ. Math. J.57.6 (2008), pp. 2611–2642.doi: 10.1512/iumj.2008.57. 3632

  4. [12]

    The initial-value problem for the Korteweg-de Vries equation

    J. L. Bona and R. Smith. “The initial-value problem for the Korteweg-de Vries equation”. In:Philos. Trans. Roy. Soc. London Ser. A278.1287 (1975), pp. 555–601.doi:10.1098/rsta.1975.0035

  5. [13]

    Stability of solitary waves in higher-order Sobolev spaces

    J. L. Bona, Y. Liu, and N. V. Nguyen. “Stability of solitary waves in higher-order Sobolev spaces”. In: Commun. Math. Sci.2.1 (2004), pp. 35–52.doi:10.4310/cms.2004.v2.n1.a3

  6. [14]

    KdV cnoidal waves are spectrally stable

    N. Bottman and B. Deconinck. “KdV cnoidal waves are spectrally stable”. In:Discrete Contin. Dyn. Syst. 25.4 (2009), pp. 1163–1180.doi:10.3934/dcds.2009.25.1163

  7. [15]

    Essai sur la th´ eorie des eaux courantes

    J. Boussinesq. “Essai sur la th´ eorie des eaux courantes”. In:Memoires presentes par divers savants l’Acad. des Sci. Inst. Nat. France24 (1877), pp. 1–680

  8. [16]

    Orbital stability of plane waves in the Klein–Gordon Equation against localized perturbations

    E. Bukieda, L. Gar´ enaux, and B. de Rijk. “Orbital stability of plane waves in the Klein–Gordon Equation against localized perturbations”. In:arXiv preprint 2506.06029(2025)

  9. [17]

    Cnoidal-type surface waves in deep water

    D. Clamond. “Cnoidal-type surface waves in deep water”. In:J. Fluid Mech.489 (2003), pp. 101–120.doi: 10.1017/S0022112003005111

  10. [18]

    On asymptotic stability in 3D of kinks for the ϕ4 model

    S. Cuccagna. “On asymptotic stability in 3D of kinks for the ϕ4 model”. In:Trans. Amer. Math. Soc.360.5 (2008), pp. 2581–2614.doi:10.1090/S0002-9947-07-04356-5

  11. [19]

    E. B. Davies.Linear operators and their spectra. Vol. 106. Cambridge Studies in Advanced Mathematics. Cambridge University Press, Cambridge, 2007, pp. xii+451.doi:10.1017/CBO9780511618864

  12. [20]

    The orbital stability of the cnoidal waves of the Korteweg-de Vries equation

    B. Deconinck and T. Kapitula. “The orbital stability of the cnoidal waves of the Korteweg-de Vries equation”. In:Phys. Lett. A374.39 (2010), pp. 4018–4022.doi:10.1016/j.physleta.2010.08.007

  13. [21]

    The dynamics of modulated wave trains

    A. Doelman, B. Sandstede, A. Scheel, and G. Schneider. “The dynamics of modulated wave trains”. In: Mem. Amer. Math. Soc.199.934 (2009), pp. viii+105.doi:10.1090/memo/0934

  14. [22]

    On the Cauchy problem for the Korteweg-de Vries equation with steplike finite-gap initial data II. Perturbations with finite moments

    I. Egorova and G. Teschl. “On the Cauchy problem for the Korteweg-de Vries equation with steplike finite-gap initial data II. Perturbations with finite moments”. In:J. Anal. Math.115 (2011), pp. 71–101.doi: 10.1007/s11854-011-0024-9

  15. [23]

    Dispersive shock waves and modulation theory

    G. A. El and M. A. Hoefer. “Dispersive shock waves and modulation theory”. In:Phys. D333 (2016), pp. 11–65.doi:10.1016/j.physd.2016.04.006

  16. [24]

    Engel and R

    K.-J. Engel and R. Nagel.One-parameter semigroups for linear evolution equations. Vol. 194. Graduate Texts in Mathematics. Springer-Verlag, New York, 2000, pp. xxii+586

  17. [25]

    M. B. Erdo˘ gan and N. Tzirakis.Dispersive partial differential equations. Vol. 86. London Mathematical Society Student Texts. Wellposedness and applications. Cambridge University Press, Cambridge, 2016, pp. xvi+186.doi:10.1017/CBO9781316563267

  18. [26]

    Orbital stability in the cubic defocusing NLS equation: I. Cnoidal periodic waves

    T. Gallay and D. Pelinovsky. “Orbital stability in the cubic defocusing NLS equation: I. Cnoidal periodic waves”. In:J. Differential Equations258.10 (2015), pp. 3607–3638.doi:10.1016/j.jde.2015.01.018

  19. [27]

    Korteweg-de Vries equation and generalization. VI. Methods for exact solution

    C. S. Gardner, J. M. Greene, M. D. Kruskal, and R. M. Miura. “Korteweg-de Vries equation and generalization. VI. Methods for exact solution”. In:Comm. Pure Appl. Math.27 (1974), pp. 97–133.doi: 10.1002/cpa. 3160270108

  20. [28]

    Orbital stability of traveling waves for the one-dimensional Gross-Pitaevskii equation

    P. G´ erard and Z. Zhang. “Orbital stability of traveling waves for the one-dimensional Gross-Pitaevskii equation”. In:J. Math. Pures Appl. (9)91.2 (2009), pp. 178–210.doi:10.1016/j.matpur.2008.09.009

  21. [29]

    Geyer and D

    A. Geyer and D. E. Pelinovsky.Stability of nonlinear waves in Hamiltonian dynamical systems. Vol. 288. Mathematical Surveys and Monographs. American Mathematical Society, Providence, RI, 2025, pp. viii+372

  22. [30]

    Stability theory of solitary waves in the presence of symmetry. I

    M. Grillakis, J. Shatah, and W. Strauss. “Stability theory of solitary waves in the presence of symmetry. I”. In:J. Funct. Anal.74.1 (1987), pp. 160–197.doi:10.1016/0022-1236(87)90044-9

  23. [31]

    Stability theory of solitary waves in the presence of symmetry. II

    M. Grillakis, J. Shatah, and W. Strauss. “Stability theory of solitary waves in the presence of symmetry. II”. In:J. Funct. Anal.94.2 (1990), pp. 308–348.doi:10.1016/0022-1236(90)90016-E

  24. [32]

    On the spectra of periodic waves for infinite-dimensional Hamiltonian systems

    M. Hˇ arˇ agu¸ s and T. Kapitula. “On the spectra of periodic waves for infinite-dimensional Hamiltonian systems”. In:Phys. D237.20 (2008), pp. 2649–2671.doi:10.1016/j.physd.2008.03.050

  25. [33]

    KdV breathers on a cnoidal wave background

    M. A. Hoefer, A. Mucalica, and D. E. Pelinovsky. “KdV breathers on a cnoidal wave background”. In:J. Phys. A56.18 (2023), Paper No. 185701, 25.doi:10.1088/1751-8121/acc6a8. 40

  26. [34]

    Orbital stability of kinks in the NLS equation with competing nonlinearities

    J. Holmer, P. G. Kevrekidis, and D. E. Pelinovsky. “Orbital stability of kinks in the NLS equation with competing nonlinearities”. In:preprint arXiv:2512.08840(2025)

  27. [35]

    Explicit solutions from eigenfunction symmetry of the Korteweg–de Vries equation

    X.-R. Hu, S.-Y. Lou, and Y. Chen. “Explicit solutions from eigenfunction symmetry of the Korteweg–de Vries equation”. In:Phys. Rev. E85 (5 2012).doi:10.1103/PhysRevE.85.056607

  28. [36]

    Dispersive decay of small data solutions for the KdV equation

    M. Ifrim, H. Koch, and D. Tataru. “Dispersive decay of small data solutions for the KdV equation”. In: Ann. Sci. ´Ec. Norm. Sup´ er. (4)56.6 (2023), pp. 1709–1746

  29. [37]

    Mixing in reaction-diffusion systems: large phase offsets

    S. Iyer and B. Sandstede. “Mixing in reaction-diffusion systems: large phase offsets”. In:Arch. Ration. Mech. Anal.233.1 (2019), pp. 323–384.doi:10.1007/s00205-019-01358-9

  30. [38]

    Weak nonlinear dispersive waves: A discussion centered around the Korteweg-de Vries equation

    A. Jeffrey and T. Kakutani. “Weak nonlinear dispersive waves: A discussion centered around the Korteweg-de Vries equation”. In:SIAM Rev.14 (1972), pp. 582–643.doi:10.1137/1014101

  31. [39]

    Recent progress on the problem of soliton resolution

    J. Jendrej. “Recent progress on the problem of soliton resolution”. In:Eur. Math. Soc. Mag.135 (2025), pp. 5–11

  32. [40]

    Nonlinear stability of periodic traveling wave solutions of the generalized Korteweg-de Vries equation

    M. A. Johnson. “Nonlinear stability of periodic traveling wave solutions of the generalized Korteweg-de Vries equation”. In:SIAM J. Math. Anal.41.5 (2009), pp. 1921–1947.doi:10.1137/090752249

  33. [41]

    Behavior of periodic solutions of viscous conservation laws under localized and nonlocalized perturbations

    M. A. Johnson, P. Noble, L. M. Rodrigues, and K. Zumbrun. “Behavior of periodic solutions of viscous conservation laws under localized and nonlocalized perturbations”. In:Invent. Math.197.1 (2014), pp. 115– 213.doi:10.1007/s00222-013-0481-0

  34. [42]

    Nonlinear stability of periodic traveling wave solutions of systems of viscous conservation laws in the generic case

    M. A. Johnson and K. Zumbrun. “Nonlinear stability of periodic traveling wave solutions of systems of viscous conservation laws in the generic case”. In:J. Differential Equations249.5 (2010), pp. 1213–1240. doi:10.1016/j.jde.2010.04.015

  35. [43]

    Nonlinear stability of viscous roll waves

    M. A. Johnson, K. Zumbrun, and P. Noble. “Nonlinear stability of viscous roll waves”. In:SIAM J. Math. Anal.43.2 (2011), pp. 577–611.doi:10.1137/100785454

  36. [44]

    Multidimensional stability of planar travelling waves

    T. Kapitula. “Multidimensional stability of planar travelling waves”. In:Trans. Amer. Math. Soc.349.1 (1997), pp. 257–269.doi:10.1090/S0002-9947-97-01668-1

  37. [45]

    Kapitula and K

    T. Kapitula and K. Promislow.Spectral and dynamical stability of nonlinear waves. Vol. 185. Applied Math- ematical Sciences. With a foreword by Christopher K. R. T. Jones. Springer, New York, 2013, pp. xiv+361. doi:10.1007/978-1-4614-6995-7

  38. [46]

    Kato.Perturbation theory for linear operators

    T. Kato.Perturbation theory for linear operators. Classics in Mathematics. Reprint of the 1980 edition. Springer-Verlag, Berlin, 1995, pp. xxii+619

  39. [47]

    On the change of form of long waves advancing in a rectangular canal, and on a new type of long stationary waves

    D. J. Korteweg and G. de Vries. “On the change of form of long waves advancing in a rectangular canal, and on a new type of long stationary waves”. In:Philos. Mag. (5)39.240 (1895), pp. 422–443.doi: 10.1080/14786449508620739

  40. [48]

    Kuchment.Floquet theory for partial differential equations

    P. Kuchment.Floquet theory for partial differential equations. Vol. 60. Operator Theory: Advances and Applications. Birkh¨ auser Verlag, Basel, 1993, pp. xiv+350.doi:10.1007/978-3-0348-8573-7

  41. [49]

    S. B. Kuksin.Analysis of Hamiltonian PDEs. Vol. 19. Oxford Lecture Series in Mathematics and its Applications. Oxford University Press, Oxford, 2000, pp. xii+212

  42. [50]

    Stability of stationary waves in nonlinear weakly dispersive media

    E. A. Kuznetsov and A. V. Mikhailov. “Stability of stationary waves in nonlinear weakly dispersive media”. In:Zh. Eksp. Teor. Fiz.67.5 (1974), pp. 1717–1727

  43. [51]

    Integrals of nonlinear equations of evolution and solitary waves

    P. D. Lax. “Integrals of nonlinear equations of evolution and solitary waves”. In:Comm. Pure Appl. Math. 21 (1968), pp. 467–490.doi:10.1002/cpa.3160210503

  44. [52]

    Periodic solutions of the KdV equation

    P. D. Lax. “Periodic solutions of the KdV equation”. In:Comm. Pure Appl. Math.28 (1975), pp. 141–188. doi:10.1002/cpa.3160280105

  45. [53]

    Lewin.Spectral theory and quantum mechanics

    M. Lewin.Spectral theory and quantum mechanics. Universitext. Translated from the 2022 French original [4454766]. Springer, Cham, 2024, pp. xii+340.doi:10.1007/978-3-031-66878-4

  46. [54]

    Stability and instability of traveling solitonic bubbles

    Z. Lin. “Stability and instability of traveling solitonic bubbles”. In:Adv. Differential Equations7.8 (2002), pp. 897–918

  47. [55]

    On the stability of KdV multi-solitons

    J. H. Maddocks and R. L. Sachs. “On the stability of KdV multi-solitons”. In:Comm. Pure Appl. Math. 46.6 (1993), pp. 867–901.doi:10.1002/cpa.3160460604

  48. [56]

    Asymptotic stability of solitons for subcritical generalized KdV equations

    Y. Martel and F. Merle. “Asymptotic stability of solitons for subcritical generalized KdV equations”. In: Arch. Ration. Mech. Anal.157.3 (2001), pp. 219–254.doi:10.1007/s002050100138

  49. [57]

    Stability for the Korteweg-de Vries equation

    H. P. McKean. “Stability for the Korteweg-de Vries equation”. In:Comm. Pure Appl. Math.30.3 (1977), pp. 347–353.doi:10.1002/cpa.3160300307

  50. [58]

    Long-time asymptotics of perturbed finite-gap Korteweg-de Vries solutions

    A. Mikikits-Leitner and G. Teschl. “Long-time asymptotics of perturbed finite-gap Korteweg-de Vries solutions”. In:J. Anal. Math.116 (2012), pp. 163–218.doi:10.1007/s11854-012-0005-7

  51. [59]

    Korteweg-de Vries equation and generalizations. II. Existence of conservation laws and constants of motion

    R. M. Miura, C. S. Gardner, and M. D. Kruskal. “Korteweg-de Vries equation and generalizations. II. Existence of conservation laws and constants of motion”. In:J. Mathematical Phys.9 (1968), pp. 1204–1209. doi:10.1063/1.1664701

  52. [60]

    Stability of line solitons for the KP-II equation in R2

    T. Mizumachi. “Stability of line solitons for the KP-II equation in R2”. In:Mem. Amer. Math. Soc.238.1125 (2015), pp. vii+95.doi:10.1090/memo/1125

  53. [61]

    Stability of line solitons for the KP-II equation in R2. II

    T. Mizumachi. “Stability of line solitons for the KP-II equation in R2. II”. In:Proc. Roy. Soc. Edinburgh Sect. A148.1 (2018), pp. 149–198.doi:10.1017/S0308210517000166

  54. [62]

    Stability of Benney-Luke line solitary waves in 2 dimensions

    T. Mizumachi and Y. Shimabukuro. “Stability of Benney-Luke line solitary waves in 2 dimensions”. In: SIAM J. Math. Anal.52.5 (2020), pp. 4238–4283.doi:10.1137/19M1253848. 41

  55. [63]

    Stability of the line soliton of the KP-II equation under periodic transverse perturbations

    T. Mizumachi and N. Tzvetkov. “Stability of the line soliton of the KP-II equation under periodic transverse perturbations”. In:Math. Ann.352.3 (2012), pp. 659–690.doi:10.1007/s00208-011-0654-3

  56. [64]

    M. V. Nezlin.Physics of intense beams in plasmas. Plasma Physics Series. IOP Publishing Ltd, 1993, pp. 1–336.doi:10.1201/9780203743300

  57. [65]

    On the Hamiltonian structure of evolution equations

    P. J. Olver. “On the Hamiltonian structure of evolution equations”. In:Math. Proc. Cambridge Philos. Soc. 88.1 (1980), pp. 71–88.doi:10.1017/S0305004100057364

  58. [66]

    Shallow water cnoidal wave interactions

    A. R. Osborne. “Shallow water cnoidal wave interactions”. In:Nonlinear Process. Geophys.1.4 (1994), pp. 241–251.doi:10.5194/npg-1-241-1994

  59. [67]

    Reed and B

    M. Reed and B. Simon.Methods of modern mathematical physics. IV. Analysis of operators. Academic Press [Harcourt Brace Jovanovich, Publishers], New York-London, 1978, pp. xv+396

  60. [68]

    Stability and dynamics of planar fronts in reaction-diffusion systems under nonlocalized perturbations

    B. de Rijk and J. van Winden. “Stability and dynamics of planar fronts in reaction-diffusion systems under nonlocalized perturbations”. In:preprint arXiv:2601.05832(2026)

  61. [69]

    Linear asymptotic stability and modulation behavior near periodic waves of the Korteweg– de Vries equation

    L. M. Rodrigues. “Linear asymptotic stability and modulation behavior near periodic waves of the Korteweg– de Vries equation”. In:J. Funct. Anal.274.9 (2018), pp. 2553–2605.doi:10.1016/j.jfa.2018.02.004

  62. [70]

    Stability and instability of the KdV solitary wave under the KP-I flow

    F. Rousset and N. Tzvetkov. “Stability and instability of the KdV solitary wave under the KP-I flow”. In: Comm. Math. Phys.313.1 (2012), pp. 155–173.doi:10.1007/s00220-012-1495-y

  63. [71]

    Diffusive mixing of periodic wave trains in reaction- diffusion systems

    B. Sandstede, A. Scheel, G. Schneider, and H. Uecker. “Diffusive mixing of periodic wave trains in reaction- diffusion systems”. In:J. Differential Equations252.5 (2012), pp. 3541–3574.doi: 10.1016/j.jde.2011.10. 014

  64. [72]

    Scarpellini.Stability, instability, and direct integrals

    B. Scarpellini.Stability, instability, and direct integrals. Vol. 402. Chapman & Hall/CRC Research Notes in Mathematics. Chapman & Hall/CRC, Boca Raton, FL, 1999, pp. xvi+346

  65. [73]

    Diffusive stability of spatial periodic solutions of the Swift-Hohenberg equation

    G. Schneider. “Diffusive stability of spatial periodic solutions of the Swift-Hohenberg equation”. In:Comm. Math. Phys.178.3 (1996), pp. 679–702

  66. [74]

    Nonlinear diffusive stability of spatially periodic solutions—abstract theorem and higher space dimensions

    G. Schneider. “Nonlinear diffusive stability of spatially periodic solutions—abstract theorem and higher space dimensions”. In:Proceedings of the International Conference on Asymptotics in Nonlinear Diffusive Systems (Sendai, 1997). Vol. 8. Tohoku Math. Publ. Tohoku Univ., Sen...

  67. [75]

    Schneider and H

    G. Schneider and H. Uecker.Nonlinear PDEs. Vol. 182. Graduate Studies in Mathematics. A dynamical systems approach. American Mathematical Society, Providence, RI, 2017, pp. xiii+575.doi: 10.1090/gsm/ 182

  68. [76]

    P. C. Schuur.Asymptotic analysis of soliton problems. Vol. 1232. Lecture Notes in Mathematics. An inverse scattering approach. Springer-Verlag, Berlin, 1986, pp. viii+180.doi:10.1007/BFb0073054

  69. [77]

    Non-linear dispersive waves

    G. B. Whitham. “Non-linear dispersive waves”. In:Proc. Roy. Soc. London Ser. A283 (1965), pp. 238–261. doi:10.1098/rspa.1965.0019

  70. [78]

    Stability for line solitary waves of Zakharov-Kuznetsov equation

    Y. Yamazaki. “Stability for line solitary waves of Zakharov-Kuznetsov equation”. In:J. Differential Equations 262.8 (2017), pp. 4336–4389.doi:10.1016/j.jde.2017.01.006

  71. [79]

    Zettl.Sturm-Liouville theory

    A. Zettl.Sturm-Liouville theory. Vol. 121. Mathematical Surveys and Monographs. American Mathematical Society, Providence, RI, 2005, pp. xii+328.doi:10.1090/surv/121

  72. [80]

    P. E. Zhidkov.Korteweg-de Vries and nonlinear Schr¨ odinger equations: qualitative theory. Vol. 1756. Lecture Notes in Mathematics. Springer-Verlag, Berlin, 2001, pp. vi+147

  73. [81]

    Forward-modulated damping estimates and nonlocalized stability of periodic Lugiato-Lefever waves

    K. Zumbrun. “Forward-modulated damping estimates and nonlocalized stability of periodic Lugiato-Lefever waves”. In:Ann. Inst. H. Poincar´ e C Anal. Non Lin´ eaire41.2 (2024), pp. 497–510.doi: 10.4171/aihpc/76. 42

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