In this paper, we investigated higher-order smooth positon and breather-positon solutions of the Kuralay equation. Starting from the associated Lax pair, we constructed an explicit $ N $-fold Darboux transformation (DT) in determinant form. By introducing a spectral parameter degeneration procedure combined with higher-order Taylor expansion, we derived smooth higher-order positon solutions from multi-soliton solutions. Furthermore, under nonvanishing boundary conditions, breather-positon solutions were obtained. The dynamical properties of these solutions were analyzed, revealing elastic interaction behavior and nontrivial phase shifts. The results provided a unified framework for constructing degenerate localized wave structures and extended existing studies on the Kuralay equation.
Citation: Maha Alammari, Muhammad Yasir, Solomon Manukure. Higher-order smooth profiles and breather-positon phenomena in the Kuralay equation[J]. AIMS Mathematics, 2026, 11(4): 11580-11594. doi: 10.3934/math.2026477
In this paper, we investigated higher-order smooth positon and breather-positon solutions of the Kuralay equation. Starting from the associated Lax pair, we constructed an explicit $ N $-fold Darboux transformation (DT) in determinant form. By introducing a spectral parameter degeneration procedure combined with higher-order Taylor expansion, we derived smooth higher-order positon solutions from multi-soliton solutions. Furthermore, under nonvanishing boundary conditions, breather-positon solutions were obtained. The dynamical properties of these solutions were analyzed, revealing elastic interaction behavior and nontrivial phase shifts. The results provided a unified framework for constructing degenerate localized wave structures and extended existing studies on the Kuralay equation.
| [1] |
Y. S. Kivshar, B. A. Malomed, Dynamics of solitons in nearly integrable systems, Rev. Mod. Phys., 61 (1989), 763. https://doi.org/10.1103/RevModPhys.61.763 doi: 10.1103/RevModPhys.61.763
|
| [2] |
M. J. Ablowitz, Z. H. Musslimani, Integrable nonlocal nonlinear Schrödinger equation, Phys. Rev. Lett., 110 (2013), 064105. https://doi.org/10.1103/PhysRevLett.110.064105 doi: 10.1103/PhysRevLett.110.064105
|
| [3] |
W. G. Zhang, M. Y. Wang, C. Song, Soliton solutions of the semi-discrete complex coupled dispersionless integrable system, Appl. Math. Lett., 113 (2021), 106859. https://doi.org/10.1016/j.aml.2020.106859 doi: 10.1016/j.aml.2020.106859
|
| [4] |
H. Ma, R. U. Rahman, S. Manukure, Dynamical analysis and bifurcations in a fractional integrable equation, Alex. Eng. J., 125 (2025), 600–623. https://doi.org/10.1016/j.aej.2025.03.138 doi: 10.1016/j.aej.2025.03.138
|
| [5] |
M. J. Ablowitz, D. J. Kaup, A. C. Newell, H. Segur, The inverse scattering transform-Fourier analysis for nonlinear problems, Stud. Appl. Math., 53 (1974), 249–315. https://doi.org/10.1002/sapm1974534249 doi: 10.1002/sapm1974534249
|
| [6] |
T. Aktosun, M. Unlu, A generalized method for the Darboux transformation, J. Math. Phys., 63 (2022), 103501. https://doi.org/10.1063/5.0092710 doi: 10.1063/5.0092710
|
| [7] |
W. Yang, C. Wang, Y. Shi, X. Xin, Construction and exact solution of the nonlocal Kuralay-Ⅱ equation via Darboux transformation, Appl. Math. Lett., 173 (2026), 109758. https://doi.org/10.1016/j.aml.2025.109758 doi: 10.1016/j.aml.2025.109758
|
| [8] |
R. U. Rahman, Z. Li, J. He, Kink-type wavefronts in some saturated ferromagnetic materials Via the Darboux transformation, Math. Method. Appl. Sci., 48 (2025), 8735–8754. https://doi.org/10.1002/mma.10750 doi: 10.1002/mma.10750
|
| [9] |
K. J. Wang, K. H. Yan, S. Li, Multi-rogue wave, generalized breathers wave, bell shape and singular wave solutions to the (3+1)-dimensional Yu-Toda-Sasa-Fukuyama equation, Math. Method. Appl. Sci., 2026. https://doi.org/10.1002/mma.70663 doi: 10.1002/mma.70663
|
| [10] | R. Hirota, The direct method in soliton theory, Cambridge: Cambridge University Press, 2004. https://doi.org/10.1017/CBO9780511543043 |
| [11] |
L. Huang, D. S. Wang, X. Zhu, Nonlinear Fourier transforms for the Sawada-Kotera equation on the line, Stud. Appl. Math., 155 (2025), e70075. https://doi.org/10.1111/sapm.70075 doi: 10.1111/sapm.70075
|
| [12] |
R. U. Rahman, J. He, Degenerate Darboux transformations and the higher-order positon solutions for the principal chiral field equation, Phys. Lett. A, 584 (2026), 131634. https://doi.org/10.1016/j.physleta.2026.131634 doi: 10.1016/j.physleta.2026.131634
|
| [13] |
K. J. Wang, K. H. Yan, J. Cheng, Y. B. Zheng, F. Shi, H. W. Zhu, et al., Bilinear form, Bäcklund transformation to the Kairat-Ⅱ-Ⅹ-extended equation: N-soliton, anti-kink soliton, novel soliton molecule, multi-lump and travelling wave solutions, Mod. Phys. Lett. B, 40 (2026), 2650057. https://doi.org/10.1142/S0217984926500570 doi: 10.1142/S0217984926500570
|
| [14] |
K. J. Wang, Exploring exact wave solutions of the Cahn-Allen equation via a novel Bernoulli sub-equation neural networks method, Mod. Phys. Lett. B, 40 (2026), 2650062. https://doi.org/10.1142/S0217984926500624 doi: 10.1142/S0217984926500624
|
| [15] | P. G. Drazin, R. S. Johnson, Solitons: An introduction, Cambridge: Cambridge University Press, 1989. https://doi.org/10.1017/CBO9781139172059 |
| [16] |
J. Yu, F. Yu, Non-autonomous soliton, wave propagation and collision dynamic for (2+1)-dimensional higher-order nonlinear Schrödinger equation with variable coefficients, Appl. Math. Lett., 174 (2026), 109827. https://doi.org/10.1016/j.aml.2025.109827 doi: 10.1016/j.aml.2025.109827
|
| [17] |
J. J. Huang, Z. L. Jia, X. L. Zhang, Nonlinear interference between solitons and nonstationary dispersive waves in a passively mode-locked fiber laser, Phys. Rev. A, 105 (2022), 053526. https://doi.org/10.1103/PhysRevA.105.053526 doi: 10.1103/PhysRevA.105.053526
|
| [18] |
Y. Qi, Q. Yu, Y. Gao, W. Wang, C. Ning, C. He, et al., Dynamics of dissipative pure-quartic solitons and molecules in NPR mode-locked fiber lasers with positive fourth-order dispersion, Chaos Soliton. Fract., 202 (2026), 117579. https://doi.org/10.1016/j.chaos.2025.117579 doi: 10.1016/j.chaos.2025.117579
|
| [19] |
Y. Tao, J. He, Multisolitons, breathers, and rogue waves for the Hirota equation generated by the Darboux transformation, Phys. Rev. E, 85 (2012), 026601. https://doi.org/10.1103/PhysRevE.85.026601 doi: 10.1103/PhysRevE.85.026601
|
| [20] |
T. Xu, Y. Wang, Y. Shan, $N$-bright-dark-soliton, the general soliton molecules and $N$-breather for the Kuralay equation, Phys. Scr., 101 (2026), 035207. https://doi.org/10.1088/1402-4896/ae35e7 doi: 10.1088/1402-4896/ae35e7
|
| [21] |
B. Kibler, J. Fatome, C. Finot, G. Millot, F. Dias, G. Genty, et al., The Peregrine soliton in nonlinear fibre optics, Nature Phys., 6 (2010), 790–795. https://doi.org/10.1038/nphys1740 doi: 10.1038/nphys1740
|
| [22] |
L. C. Zhao, L. Ling, Z. Y. Yang, Mechanism of Kuznetsov-Ma breathers, Phys. Rev. E, 97 (2018), 022218. https://doi.org/10.1103/PhysRevE.97.022218 doi: 10.1103/PhysRevE.97.022218
|
| [23] |
J. He, H. R. Zhang, L. H. Wang, K. Porsezian, A. S. Fokas, Generating mechanism for higher-order rogue waves, Phys. Rev. E, 87 (2013), 052914. https://doi.org/10.1103/PhysRevE.87.052914 doi: 10.1103/PhysRevE.87.052914
|
| [24] |
D. Wang, Z. Liu, H. Zhao, H. Qin, G. Bai, C. Chen, et al., Launching by cavitation, Science, 389 (2025), 935–939. https://doi.org/10.1126/science.adu8943 doi: 10.1126/science.adu8943
|
| [25] |
Y. H. Jia, Z. Z. Si, Z. T. Ju, H. Y. Feng, J. H. Zhang, X. Yan, et al., Convolutional-recurrent neural network for the prediction of formation and switching dynamics for multicolor solitons, Sci. China Phys. Mech. Astron., 68 (2025), 284211. https://doi.org/10.1007/s11433-025-2679-8 doi: 10.1007/s11433-025-2679-8
|
| [26] |
V. B. Matveev, Positons: Slowly decreasing analogues of solitons, Theor. Math. Phys., 131 (2002), 483–497. https://doi.org/10.1023/A:1015149618529 doi: 10.1023/A:1015149618529
|
| [27] |
R. U. Rahman, Z. Li, J. He, Magnetic wave dynamics in ferromagnetic thin films: Interactions of solitons and positons in Landau-Lifshitz-Gilbert equation, Physica D, 479 (2025), 134719. https://doi.org/10.1016/j.physd.2025.134719 doi: 10.1016/j.physd.2025.134719
|
| [28] |
J. Wu, Y. Zhang, X. Wang, J. Wang, Positon and breather positon solutions for the nonlocal higher-order Chen-Lee-Liu equation, Phys. Lett. A, 552 (2025), 130630. https://doi.org/10.1016/j.physleta.2025.130630 doi: 10.1016/j.physleta.2025.130630
|
| [29] |
N. V. Priya, S. Monisha, M. Senthilvelan, G. Rangarajan, Nth-order smooth positon and breather-positon solutions of a generalized nonlinear Schrödinger equation, Eur. Phys. J. Plus, 137 (2022), 646. https://doi.org/10.1140/epjp/s13360-022-02861-x doi: 10.1140/epjp/s13360-022-02861-x
|
| [30] |
Y. Zhong, Y. Zhang, Rogue waves on the periodic background of the Kuralay-Ⅱ equation, Wave Motion, 128 (2024), 103310. https://doi.org/10.1016/j.wavemoti.2024.103310 doi: 10.1016/j.wavemoti.2024.103310
|
| [31] |
Z. Sagidullayeva, G. Nugmanova, R. Myrzakulov, N. Serikbayev, Integrable Kuralay equations: Geometry, solutions and generalizations, Symmetry, 14 (2022), 1374. https://doi.org/10.3390/sym14071374 doi: 10.3390/sym14071374
|
| [32] |
Y. Zhong, Y. Zhang, Multi-breather solutions on the periodic background of the Kuralay-Ⅱ equation, Phys. Lett. A, 567 (2025), 131208. https://doi.org/10.1016/j.physleta.2025.131208 doi: 10.1016/j.physleta.2025.131208
|
| [33] |
H. An, Z. Liu, M. Yuen, Novel localized vector wave solutions in the Kuralay-Ⅱ equation, Nonlinear Dyn., 113 (2025), 23395–23412. https://doi.org/10.1007/s11071-025-11267-0 doi: 10.1007/s11071-025-11267-0
|
| [34] |
S. O. Abbas, S. Shabbir, S. T. R. Rizvi, A. R. Seadawy, Optical dromions for M-fractional Kuralay equation via complete discrimination system approach along with sensitivity analysis and quasi-periodic behavior, Mod. Phys. Lett. B, 39 (2025), 2550048. https://doi.org/10.1142/S0217984925500484 doi: 10.1142/S0217984925500484
|
| [35] |
A. Hussain, T. F. Ibrahim, M. M. Bashier, W. M. Osman, A. A. Dawood, The profile of soliton molecules for integrable complex coupled Kuralay equations, Phys. Scr., 100 (2025), 015259. https://doi.org/10.1088/1402-4896/ad999d doi: 10.1088/1402-4896/ad999d
|
| [36] |
W. A. Faridi, Z. Myrzakulova, R. Myrzakulov, A. Akgül, M. S. Osman, The construction of exact solution and explicit propagating optical soliton waves of Kuralay equation by the new extended direct algebraic and Nucci's reduction techniques, Int. J. Model. Simulat., 45 (2025), 2012–2031. https://doi.org/10.1080/02286203.2024.2315278 doi: 10.1080/02286203.2024.2315278
|
| [37] |
J. He, L. Zhang, Y. Cheng, Y. Li, Determinant representation of Darboux transformation for the AKNS system, Sci. China Ser. A, 49 (2006), 1867–1878. https://doi.org/10.1007/s11425-006-2025-1 doi: 10.1007/s11425-006-2025-1
|