We studied a stochastic heat equation with proportional space-time delay and scalar multiplicative Brownian noise. The model described diffusion with scale-dependent memory, where delayed feedback was evaluated at spatially rescaled locations. A key feature was that the associated spatial pantograph operator is non-isometric, leading to an additional spatial-compression effect in the mean-square stability condition. We established well-posedness, mean-square boundedness, and algebraic mean-square decay under suitable stability assumptions. For the numerical approximation, we developed a semi-implicit finite-difference Euler-Maruyama method that treated diffusion and damping implicitly while evaluating the delayed and stochastic terms explicitly. Under appropriate interpolation and step-size assumptions, the scheme preserved mean-square boundedness and algebraic decay and achieved second-order spatial accuracy and the classical one-half strong temporal order. Numerical experiments supported the theoretical results, demonstrated the effectiveness of the semi-implicit treatment of stiffness, and quantified the influence of spatial compression on the stability margin.
Citation: Fathalla A. Rihan. Mean-square stability and semi-implicit Euler-Maruyama approximation of a stochastic pantograph heat equation with proportional space-time delay[J]. AIMS Mathematics, 2026, 11(9): 30233-30259. doi: 10.3934/math.20261198
We studied a stochastic heat equation with proportional space-time delay and scalar multiplicative Brownian noise. The model described diffusion with scale-dependent memory, where delayed feedback was evaluated at spatially rescaled locations. A key feature was that the associated spatial pantograph operator is non-isometric, leading to an additional spatial-compression effect in the mean-square stability condition. We established well-posedness, mean-square boundedness, and algebraic mean-square decay under suitable stability assumptions. For the numerical approximation, we developed a semi-implicit finite-difference Euler-Maruyama method that treated diffusion and damping implicitly while evaluating the delayed and stochastic terms explicitly. Under appropriate interpolation and step-size assumptions, the scheme preserved mean-square boundedness and algebraic decay and achieved second-order spatial accuracy and the classical one-half strong temporal order. Numerical experiments supported the theoretical results, demonstrated the effectiveness of the semi-implicit treatment of stiffness, and quantified the influence of spatial compression on the stability margin.
| [1] | J. R. Ockendon, A. B. Tayler, The dynamics of a current collection system for an electric locomotive, Proc. R. Soc. Lond. Ser. A Math. Phys. Sci., 322 (1971), 447–468. |
| [2] |
A. Iserles, On the generalized pantograph functional-differential equation, Eur. J. Appl. Math., 4 (1993), 1–38. https://doi.org/10.1017/S0956792500000966 doi: 10.1017/S0956792500000966
|
| [3] | F. A. Rihan, Delay differential equations and applications to biology, 2 Eds., Cham: Springer, 2026. https://doi.org/10.1007/978-3-032-08645-7 |
| [4] | A. D. Polyanin, V. G. Sorokin, Exact solutions and reductions of nonlinear diffusion PDEs of pantograph type, 2021, arXiv: 2103.01666. |
| [5] |
F. A. Rihan, A. F. Rihan, An analysis of the theta-method for pantograph-type delay differential equations, Complexity, 2022 (2022), 8961352. https://doi.org/10.1155/2022/8961352 doi: 10.1155/2022/8961352
|
| [6] |
F. A. Rihan, Continuous Runge-Kutta schemes for pantograph type delay differential equations, Partial Differ. Equ. Appl. Math., 11 (2024), 100797. https://doi.org/10.1016/j.padiff.2024.100797 doi: 10.1016/j.padiff.2024.100797
|
| [7] |
F. A. Rihan, K. Udhayakumar, Split-step $\theta$-method for stochastic pantograph differential equations: convergence and mean-square stability analysis, Appl. Numer. Math., 217 (2025), 1–17. https://doi.org/10.1016/j.apnum.2025.05.010 doi: 10.1016/j.apnum.2025.05.010
|
| [8] |
J. Alzabut, A. G. M. Selvam, R. A. El-Nabulsi, D. Dhakshinamoorthy, M. E. Samei, Asymptotic stability of nonlinear discrete fractional pantograph equations with non-local initial conditions, Symmetry, 13 (2021), 1–22. https://doi.org/10.3390/sym13030473 doi: 10.3390/sym13030473
|
| [9] |
T. S. Hassan, R. G. Ahmed, A. M. A. El-Sayed, R. A. El-Nabulsi, O. Moaaz, M. B. Mesmouli, Solvability of a state-dependence functional integro-differential inclusion with delay nonlocal condition, Mathematics, 10 (2022), 1–18. https://doi.org/10.3390/math10142420 doi: 10.3390/math10142420
|
| [10] |
S. S. Santra, R. A. El-Nabulsi, K. M. Khedher, Oscillation of second-order differential equations with multiple and mixed delays under a canonical operator, Mathematics, 9 (2021), 1–9. https://doi.org/10.3390/math9121323 doi: 10.3390/math9121323
|
| [11] |
A. Shahid, H. L. Huang, M. M. Bhatti, M. Marin, Numerical computation of magnetized bioconvection nanofluid flow with temperature-dependent viscosity and Arrhenius kinetic, Math. Comput. Simul., 200 (2022), 377–392. https://doi.org/10.1016/j.matcom.2022.04.032 doi: 10.1016/j.matcom.2022.04.032
|
| [12] |
S. Askar, A. E. Abouelregal, M. Marin, A. Foul, Photo-thermoelasticity heat transfer modeling with fractional differential actuators for stimulated nano-semiconductor media, Symmetry, 15 (2023), 1–18. https://doi.org/10.3390/sym15030656 doi: 10.3390/sym15030656
|
| [13] | S. E. A. Mohammed, Stochastic functional differential equations, Boston: Pitman, 1984. |
| [14] | G. Da Prato, J. Zabczyk, Stochastic equations in infinite dimensions, Cambridge University Press, 1992. |
| [15] | C. Prévôt, M. Röckner, A concise course on stochastic partial differential equations, Berlin, Heidelberg: Springer, 2007. https://doi.org/10.1007/978-3-540-70781-3 |
| [16] | X. R. Mao, Stochastic differential equations and applications, 2 Eds., Chichester: Horwood Publishing, 2007. |
| [17] |
G. A. Bocharov, F. A. Rihan, Numerical modelling in biosciences using delay differential equations, J. Comput. Appl. Math., 125 (2000), 183–199. https://doi.org/10.1016/S0377-0427(00)00468-4 doi: 10.1016/S0377-0427(00)00468-4
|
| [18] | A. Bellen, M. Zennaro, Numerical methods for delay differential equations, Oxford University Press, 2003. |
| [19] |
C. T. H. Baker, C. A. H. Paul, D. R. Willé, Issues in the numerical solution of evolutionary delay differential equations, Adv. Comput. Math., 3 (1995), 171–196. https://doi.org/10.1007/BF02988625 doi: 10.1007/BF02988625
|
| [20] |
W. H. Enright, H. Hayashi, A delay differential equation solver based on a continuous Runge-Kutta method with defect control, Numer. Algorithms, 16 (1997), 349–364. https://doi.org/10.1023/A:1019107718128 doi: 10.1023/A:1019107718128
|
| [21] |
W. H. Enright, H. Hayashi, Convergence analysis of the solution of retarded and neutral delay differential equations by continuous numerical methods, SIAM J. Numer. Anal., 35 (1998), 572–585. https://doi.org/10.1137/S0036142996302049 doi: 10.1137/S0036142996302049
|
| [22] | P. E. Kloeden, E. Platen, Numerical solution of stochastic differential equations, Berlin, Heidelberg: Springer, 1992. https://doi.org/10.1007/978-3-662-12616-5 |
| [23] | G. N. Milstein, Numerical integration of stochastic differential equations, Dordrecht: Springer, 1995. |
| [24] |
D. J. Higham, An algorithmic introduction to numerical simulation of stochastic differential equations, SIAM Rev., 43 (2001), 525–546. https://doi.org/10.1137/S0036144500378302 doi: 10.1137/S0036144500378302
|