文摘
Nonlinear parabolic equation is studied with a linearized Galerkin finite element method. First of all, a time-discrete system is established to split the error into two parts which are called the temporal error and the spatial error, respectively. On one hand, a rigorous analysis for the regularity of the time-discrete system is presented based on the proof of the temporal error skillfully. On the other hand, the spatial error is derived \(\tau \)-independently with the above achievements. Then, the superclose result of order \(O(h^2+\tau ^2)\) in broken \(H^1\)-norm is deduced without any restriction of \(\tau \). The two typical characters of the \({\textit{EQ}}_1^{rot}\) nonconforming FE (see Lemma 1 below) play an important role in the procedure of proof. At last, numerical results are provided in the last section to confirm the theoretical analysis. Here, h is the subdivision parameter, and \(\tau \), the time step.