Two-grid mixed virtual element method for a nonlinear fourth-order time-fractional reaction-diffusion equation
Jianmei Chen , Xinyuan Liu , Yang Liu
Communications in Analysis and Mechanics ›› 2026, Vol. 18 ›› Issue (2) : 476 -510.
In this article, we developed a two-grid mixed virtual element method (MVEM) for solving a time-dependent fourth-order reaction-diffusion equation with a Riemann-Liouville fractional derivative and a nonlinear reaction term. By introducing an auxiliary variable σ = ∆u, we reformulated the problem into a coupled system of second-order equations. Then we discretized the equations at tk−α by a second-order backward differentiation formula (BDF2) with a fractional parameter α. The method employed a two-grid strategy: First, we solved a nonlinear problem via Newton iterations on a coarse ploygonal grid, and subsequently, leveraging the coarse-grid solutions, we solved a linearized problem on a fine virtual element space. We established the stability of this method and derived a priori L2-norm error estimates with the optimal convergence result O(∆t2 + hk+1 + H2k+2), where ∆t denotes the time step size, h and H are the fine and coarse spatial mesh sizes, respectively, and k is the polynomial degree of the virtual element space. Numerical experiments validated the theoretical convergence rates, and it was demonstrated that applying the two-grid MVEM is computationally more efficient than solving the nonlinear system directly on the fine grid.
two-grid mixed virtual element method / fourth-order time-fractional reaction-diffusion equation / a priori error analysis in L2-norm / unstructured meshes
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| [2] |
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| [3] |
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| [4] |
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| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
|
| [36] |
|
| [37] |
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