With an error compensation term in the fractal Rayleigh quotient of PDE eigen-problems,we propose a new scheme by perturbing the mass matrix Mhto Mh=Mh+Ch2mKh,where Khis the corresponding stif matrix of a 2m 1 degree ...With an error compensation term in the fractal Rayleigh quotient of PDE eigen-problems,we propose a new scheme by perturbing the mass matrix Mhto Mh=Mh+Ch2mKh,where Khis the corresponding stif matrix of a 2m 1 degree conforming finite element with mesh size h for a 2m-order self-adjoint PDE,and the constant C exists in the priority error estimationλh jλj^Ch2mλ2j.In particular,for Laplace eigenproblems over regular domains in uniform mesh,e.g.,cube,equilateral triangle and regular hexagon,etc.,we find the constant C=I h 1Mh2 hKh and show that in this case the computation accuracy can raise two orders,i.e.,fromλh jλj=O(h2)to O(h4).Some numerical tests in 2-D and 3-D are given to verify the above arguments.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos.60970089,61170075 and 91230109)
文摘With an error compensation term in the fractal Rayleigh quotient of PDE eigen-problems,we propose a new scheme by perturbing the mass matrix Mhto Mh=Mh+Ch2mKh,where Khis the corresponding stif matrix of a 2m 1 degree conforming finite element with mesh size h for a 2m-order self-adjoint PDE,and the constant C exists in the priority error estimationλh jλj^Ch2mλ2j.In particular,for Laplace eigenproblems over regular domains in uniform mesh,e.g.,cube,equilateral triangle and regular hexagon,etc.,we find the constant C=I h 1Mh2 hKh and show that in this case the computation accuracy can raise two orders,i.e.,fromλh jλj=O(h2)to O(h4).Some numerical tests in 2-D and 3-D are given to verify the above arguments.
