Abstract
In this paper, several equivalent systems without constraints of the indefinite least squares problem with equality constraints (ILSE) are established. We also derive the perturbation results for the ILSE problem and illustrate our results with numerical tests.
Acknowledgements
The work of Qiaohua Liu was supported by Shanghai Municipal R&D Special-purpose Grant for Selectively Culturing Excellent Young Teachers in Universities and Colleges (B. 99-0303-06-040) and Shanghai Municipal Education Commission (06AZ088). The work of Minghui Wang was supported by NSFC under grant no. 10771073.