چكيده فارسي :
There are some different types of BPX multilevel precoditioners
that are used for elliptic problems. In the most effective type, we need to
compute the largest eigenvalues of the stiffness matrices in each level where
is resulted from discretization of a variational boundary value problem.
However, in the large scales, determining the eigenvalues of the stiffness
matrix in the finest level is not generally easy except for some especial matrices
. In this paper, we present a kind of BPX multilevel preconditioner
which is suitable for symmetric positive definite system. In fact, with a
change in the BPX preconditioner, we find a new preconditioner which is
suitable for large scales.
