A norm bound for projections with complex weights
Elena Y. Bobrovnikova, Stephen A. Vavasis · Linear Algebra and its Applications · 2000
We consider projections weighted by a complex diagonal matrix. These projections arise in the solution of alternating-current (AC) electrical networks. A norm bound for weighted projections in the case of an ill-conditioned real positive-definite weight matrix was established by Dikin, Stewart, Todd and others. We show that this bound generalizes to the complex case.