SIAM Journal on Matrix Analysis and Applications
When the isotypic subspaces of a representation are viewed as the eigenspaces of a symmetric linear transformation, isotypic projections may be achieved as eigenspace projections and computed using the Lanczos iteration. In this paper, we show how this approach gives rise to an efficient isotypic projection method for permutation representations of distance transitive graphs and the symmetric group.
Maslen, David K.; Orrison, Michael E.; and Rockmore, Daniel N., "Computing Isotypic Projections with the Lanczos Iteration" (2004). Open Dartmouth: Faculty Open Access Articles. 2471.