A fast wavelet multigrid algorithm for solution of electromagnetic integral equations

A multigrid scheme naturally contained in wavelet expansion methods is pres ented. Careful examination of the wavelet matrix reveals matrix representat ions of an integral operator at various coarse levels that can be identifie d as nested submatrices of the original wavelet matrix at the finest level. Hence, this wavelet multigrid scheme entails no additional computational e fforts for the construction of coarser representations. Moreover, this wave let multigrid algorithm fully exploits the wavelet matrix structures-sparsi ty and multiscale representation. Numerical examples show that this wavelet multigrid scheme offers a fast and robust technique for electromagnetic fi eld computations in unbounded regions. (C) 2000 John Wiley & Sons, Inc.