English

On the Relationship Between Real and Complex Linear Systems

Rings and Algebras 2017-06-02 v1 Numerical Analysis

Abstract

We consider the problem of solving a linear system of equations which involves complex variables and their conjugates. We characterize when it reduces to a complex linear system, that is, a system involving only complex variables (and not their conjugates). In that case, we show how to construct the complex linear system. Interestingly, this provides a new insight on the relationship between real and complex linear systems. In particular, any real symmetric linear system of equations can be solved via a complex linear system of equations. Numerical illustrations are provided. The mathematics in this manuscript constitute an exciting interplay between Schur's complement, Cholesky's factorization, and Cauchy's interlace theorem.

Keywords

Cite

@article{arxiv.1706.00268,
  title  = {On the Relationship Between Real and Complex Linear Systems},
  author = {Cédric Josz},
  journal= {arXiv preprint arXiv:1706.00268},
  year   = {2017}
}
R2 v1 2026-06-22T20:06:07.727Z