【摘要】 文章提出了周期边界条件下四阶特征值问题的一种有效的Fourier谱逼近方法.首先,根据周期边界条件引入了适当的Sobolev空间和相应的逼近空间,建立了原问题的一种弱形式及其离散格式,并推导了等价的算子形式.其次,定义了正交投影算子,并证明了其逼近性质,结合紧算子的谱理论证明了逼近特征值的误差估计.另外,构造了逼近空间中的一组基函数,推导了离散格式基于张量积的矩阵形式.最后,文章给出了一些数值算例,数值结果表明其算法是有效的和谱精度的.更多还原

【Abstract】 In this paper,we put forward an effective Fourier spectral approximation method for fourth-order eigenvalue problems with periodic boundary conditions.Firstly,we introduce the appropriate Sobolev space and the corresponding approximation space according to the periodic boundary conditions,establish a weak form of the original problem and its discrete form,and derive the equivalent operator form.Then we define an orthogonal projection operator and prove its approximation properties.Combined with the spectral theory of compact operators,we prove the error estimates of approximation eigenvalues.In addition,we construct a set of basis functions of the approximation space,and derive the matrix form based on tensor product associated with the discrete scheme.Finally,we provide some numerical examples,and the numerical results show our algorithm is effective and spectral accuracy.更多还原