Time-fractional Dirac-type systems arise in quantum field theory, plasma physics, and condensed matter systems where fractional calculus captures nonlocal interactions. In this study, we employ classical and nonclassical Lie symmetry methods to analyze the underlying symmetry structure of the system. By deriving infinitesimal generators and performing similarity reductions, we transform the governing fractional partial differential equations (FPDEs) into fractional ordinary differential equations (FODEs). Exact solutions are constructed using the power series method. Furthermore, we establish conservation laws in the fractional setting, ensuring the physical consistency of the system. Our findings offer new insights into the interplay among symmetry, conservation principles, and exact solutions in fractional quantum field models, expanding the analytical toolkit for studying nonlinear relativistic wave equations.
Citation: Farzaneh Alizadeh, Samad Kheybari, Kamyar Hosseini. Exact solutions and conservation laws for the time-fractional nonlinear dirac system: A study of classical and nonclassical lie symmetries[J]. AIMS Mathematics, 2025, 10(5): 11757-11782. doi: 10.3934/math.2025532
Time-fractional Dirac-type systems arise in quantum field theory, plasma physics, and condensed matter systems where fractional calculus captures nonlocal interactions. In this study, we employ classical and nonclassical Lie symmetry methods to analyze the underlying symmetry structure of the system. By deriving infinitesimal generators and performing similarity reductions, we transform the governing fractional partial differential equations (FPDEs) into fractional ordinary differential equations (FODEs). Exact solutions are constructed using the power series method. Furthermore, we establish conservation laws in the fractional setting, ensuring the physical consistency of the system. Our findings offer new insights into the interplay among symmetry, conservation principles, and exact solutions in fractional quantum field models, expanding the analytical toolkit for studying nonlinear relativistic wave equations.
| [1] |
S. D. Lin, C. H. Lu, Laplace transform for solving some families of fractional differential equations and its applications, Adv. Differ. Equ. , 2013 (2013), 137. http://doi.org/10.1186/1687-1847-2013-137 doi: 10.1186/1687-1847-2013-137
|
| [2] | A. S. Vatsala, B. Sambandham, Laplace transform method for sequential Caputo fractional differential equations, Math. Eng. Sci. Aerospace, 2016. |
| [3] |
H. M. Fahad, M. Ur Rehman, A. Fernandez, On Laplace transforms with respect to functions and their applications to fractional differential equations, Math. Method. Appl. Sci. , 46 (2023), 8304–8323. https://doi.org/10.1002/mma.7772 doi: 10.1002/mma.7772
|
| [4] |
J. Cang, Y. Tan, H. Xu, S. Liao, Series solutions of non-linear Riccati differential equations with fractional order, Chaos Soliton. Fract. , 40 (2009), 1–9. https://doi.org/10.1016/j.chaos.2007.04.018 doi: 10.1016/j.chaos.2007.04.018
|
| [5] |
C. N. Angstmann, B. I. Henry, Generalized fractional power series solutions for fractional differential equations, Appl. Math. Lett. , 102 (2020), 106107. https://doi.org/10.1016/j.aml.2019.106107 doi: 10.1016/j.aml.2019.106107
|
| [6] |
A. I. Ali, M. Kalim, A. Khan, Solution of fractional partial differential equations using fractional power series method, Int. J. Differ. Equ. , 2021 (2021), 6385799. https://doi.org/10.1155/2021/6385799 doi: 10.1155/2021/6385799
|
| [7] |
M. A. Tashtoush, I. A. Ibrahim, W. M. Taha, M. H. Dawi, A. F. Jameel, E. A. Az-Zo'bi, Various closed-form solitonic wave solutions of conformable higher-dimensional Fokas model in fluids and plasma physics, Iraqi J. Comput. Sci. Math. , 5 (2024), 18. https://doi.org/10.52866/ijcsm.2024.05.03.027 doi: 10.52866/ijcsm.2024.05.03.027
|
| [8] |
R. Ur Rahman, Z. Hammouch, A. S. A. Alsubaie, K. H. Mahmoud, A. Alshehri, E. A. Az-Zo'bi, et al., Dynamical behavior of fractional nonlinear dispersive equation in Murnaghan's rod materials, Results Phys. , 56 (2024), 107207. https://doi.org/10.1016/j.rinp.2023.107207 doi: 10.1016/j.rinp.2023.107207
|
| [9] |
S. Kheybari, M. T. Darvishi, M. S. Hashemi, A semi-analytical approach to Caputo type time-fractional modified anomalous sub-diffusion equations, Appl. Numer. Math. , 158 (2020), 103–122. https://doi.org/10.1016/j.apnum.2020.07.023 doi: 10.1016/j.apnum.2020.07.023
|
| [10] |
S. Kheybari, Numerical algorithm to Caputo type time-space fractional partial differential equations with variable coefficients, Math. Comput. Simulat. , 182 (2021), 66–85. https://doi.org/10.1016/j.matcom.2020.10.018 doi: 10.1016/j.matcom.2020.10.018
|
| [11] |
M. S. Hashemi, M. Mirzazadeh, D. Baleanu, Innovative method for computing approximate solutions of non-homogeneous wave equations with generalized fractional derivatives, Contemp. Math. , 4 (2023), 1026–1047. https://doi.org/10.37256/cm.4420233593 doi: 10.37256/cm.4420233593
|
| [12] |
S. Javeed, D. Baleanu, A. Waheed, M. S. Khan, H. Affan, Analysis of homotopy perturbation method for solving fractional order differential equations, Mathematics, 7 (2019), 40. https://doi.org/10.3390/math7010040 doi: 10.3390/math7010040
|
| [13] |
J. Li, Explicit and structure-preserving exponential wave integrator fourier pseudo-spectral methods for the Dirac equation in the simultaneously massless and nonrelativistic regime, Calcolo, 61 (2024), 3. https://doi.org/10.1007/s10092-023-00554-0 doi: 10.1007/s10092-023-00554-0
|
| [14] |
J. Li, L. Zhu, A uniformly accurate exponential wave integrator fourier pseudo-spectral method with structure-preservation for long-time dynamics of the Dirac equation with small potentials, Numer. Algor. , 92 (2023), 1367–1401. https://doi.org/10.1007/s11075-022-01345-4 doi: 10.1007/s11075-022-01345-4
|
| [15] |
J. Li, T. Wang, Optimal point-wise error estimate of two conservative fourth-order compact finite difference schemes for the nonlinear Dirac equation, Appl. Numer. Math. , 162 (2021), 150–170. https://doi.org/10.1016/j.apnum.2020.12.010 doi: 10.1016/j.apnum.2020.12.010
|
| [16] |
W. Alhejaili, E. A. Az-Zo'bi, R. Shah, S. A. El-Tantawy, On the analytical soliton approximations to fractional forced korteweg–de vries equation arising in fluids and plasmas using two novel techniques, Commun. Theor. Phys. , 76 (2024), 085001. https://doi.org/10.1088/1572-9494/ad53bc doi: 10.1088/1572-9494/ad53bc
|
| [17] |
J. Yu, Y. Feng, On the generalized time fractional reaction-diffusion equation: Lie symmetries, exact solutions and conservation laws, Chaos Soliton. Fract. , 182 (2024), 114855. https://doi.org/10.1016/j.chaos.2024.114855 doi: 10.1016/j.chaos.2024.114855
|
| [18] |
J. Yu, Y. Feng, Lie symmetry analysis, power series solutions and conservation laws of (2+1)-dimensional time fractional modified Bogoyavlenskii–Schiff equations, J. Nonlinear Math. Phys. , 31 (2024), 27. https://doi.org/10.1007/s44198-024-00195-z doi: 10.1007/s44198-024-00195-z
|
| [19] |
J. Yu, Y. Feng, Group classification of time fractional Black–Scholes equation with time-dependent coefficients, Fract. Calc. Appl. Anal. , 27 (2024), 2335–2358. https://doi.org/10.1007/s13540-024-00339-4 doi: 10.1007/s13540-024-00339-4
|
| [20] | P. J. Olver, Applications of Lie groups to differential equations, New York: Springer, 1993. https://doi.org/10.1007/978-1-4612-4350-2 |
| [21] | G. W. Bluman, S. C. Anco, Symmetry and integration methods for differential equations, New York: Springer, 2002. https://doi.org/10.1007/b97380 |
| [22] | N. H. Ibragimov, CRC handbook of lie group analysis of differential equations, New York: CRC press, 1993. https://doi.org/10.1201/9781003419808 |
| [23] | W. Ma, Binary nonlinearization for the Dirac systems, 1995. arXiv: solv-int/9512002v1. https://doi.org/10.48550/arXiv.solv-int/9512002 |
| [24] |
W. Ma, K. Li, Virasoro symmetry algebra of Dirac soliton hierarchy, Inverse Probl. , 12 (1996), L25. https://doi.org/10.1088/0266-5611/12/6/001 doi: 10.1088/0266-5611/12/6/001
|
| [25] |
E. G. Fan, N-fold Darboux transformation and soliton solutions for a nonlinear Dirac system, J. Phys. A: Math. Gen. , 38 (2005), 1063. https://doi.org/10.1088/0305-4470/38/5/008 doi: 10.1088/0305-4470/38/5/008
|
| [26] | I. S. Frolov, Inverse scattering problem for a Dirac system on the whole axis, Dokl. Akad. Nauk, 207 (1972), 44–47. |
| [27] |
K. Schratz, Y. Wang, X. Zhao, Low-regularity integrators for nonlinear Dirac equations, Math. Comp, 90 (2021), 189–214. https://doi.org/10.1090/mcom/3557 doi: 10.1090/mcom/3557
|
| [28] |
F. Zhang, X. Xin, Y. Zhang, Nonlocal symmetries, exact solutions, and conservation laws for the nonlinear Dirac system, Comput. Appl. Math. , 44 (2025), 99. https://doi.org/10.1007/s40314-024-03067-w doi: 10.1007/s40314-024-03067-w
|
| [29] | A. A. Kilbas, H. M. Srivastava, J. J. Trujillo, Theory and applications of fractional differential equations, Amsterdam: Elsevier, 2006. |
| [30] | K. Diethelm, The analysis of fractional differential equations, New York: Springer, 2010. |
| [31] | S. G. Samko, Fractional integrals and derivatives, Yverdon: Gordon and Breach, 1993. |
| [32] | K. S. Miller, B. Ross, An introduction to the fractional calculus and fractional differential equations, Wiley-Interscience, 1993. |
| [33] | S. Kazem, Exact solution of some linear fractional differential equations by Laplace transform, Int. J. Nonlinear Sci. , 16 (2013), 3–11. |
| [34] |
G. D. Medina, N. R. Ojeda, J. H. Pereira, L.G. Romero, Fractional Laplace transform and fractional calculus, Int. Math. Forum, 12 (2017), 991–1000. https://doi.org/10.12988/imf.2017.71194 doi: 10.12988/imf.2017.71194
|
| [35] | C. A. Monje, Y. Chen, B. M. Vinagre, D. Xue, V. Feliu, Fractional-order systems and controls: Fundamentals and applications, New York: Springer, 2010. |
| [36] | G. W. Bluman, J. D. Cole, The general similarity solution of the heat equation, J. Math. Mech. , 18 (1969), 1025–1042. |
| [37] |
N. H. Ibragimov, A new conservation theorem, J. Math. Anal. Appl. , 333 (2007), 311–328. https://doi.org/10.1016/j.jmaa.2006.10.078 doi: 10.1016/j.jmaa.2006.10.078
|
| [38] |
R. K. Gazizov, N. H. Ibragimov, S. Y. Lukashchuk, Nonlinear self-adjointness, conservation laws and exact solutions of time-fractional Kompaneets equations, Commun. Nonlinear Sci. , 23 (2015), 153–163. https://doi.org/10.1016/j.cnsns.2014.11.010 doi: 10.1016/j.cnsns.2014.11.010
|
| [39] |
N. H. Ibragimov, Conservation laws and non-invariant solutions of anisotropic wave equations with a source, Nonlinear Anal.-Real, 40 (2018), 82–94. https://doi.org/10.1016/j.nonrwa.2017.08.005 doi: 10.1016/j.nonrwa.2017.08.005
|
| [40] |
M. S. Hashemi, A. Haji-Badali, F. Alizadeh, M. Inc, Classical and non-classical lie symmetry analysis, conservation laws and exact solutions of the time-fractional Chen–Lee–Liu equation, Comput. Appl. Math. , 42 (2023), 73. https://doi.org/10.1007/s40314-023-02217-w doi: 10.1007/s40314-023-02217-w
|
| [41] |
M. S. Hashemi, A. Haji-Badali, F. Alizadeh, X. J. Yang, Non-classical lie symmetries for nonlinear time-fractional Heisenberg equations, Math. Method. Appl. Sci. , 45 (2022), 10010–10026. https://doi.org/10.1002/mma.8353 doi: 10.1002/mma.8353
|
| [42] |
F. Alizadeh, M. S. Hashemi, A. H. Badali, Lie symmetries, exact solutions, and conservation laws of the nonlinear time-fractional Benjamin–Ono equation, Comput. Method. Differ. Equ. , 10 (2022), 608–616. https://doi.org/10.22034/cmde.2021.45436.1911 doi: 10.22034/cmde.2021.45436.1911
|
| [43] |
F. Alizadeh, E. Hincal, K. Hosseini, M. S. Hashemi, A. Das, The (2+1)-dimensional generalized time-fractional Zakharov Kuznetsov Benjamin Bona Mahony equation: its classical and nonclassical symmetries, exact solutions, and conservation laws, Opt. Quant. Electron. , 55 (2023), 1061. https://doi.org/10.1007/s11082-023-05387-3 doi: 10.1007/s11082-023-05387-3
|