Editing Matrix decomposition (section)

=== Sectoral decomposition ===
*Applicable to: square, complex matrix ''A'' with [[numerical range]] contained in the sector <math>S_\alpha = \left\{r e^{i \theta} \in \mathbb{C} \mid r> 0, |\theta| \le \alpha < \frac{\pi}{2}\right\}</math>.
*Decomposition: <math>A = CZC^*</math>, where ''C'' is an invertible complex matrix and <math>Z = \operatorname{diag}\left(e^{i\theta_1},\ldots,e^{i\theta_n}\right)</math> with all <math>\left|\theta_j\right| \le \alpha </math>.<ref name=Zhang2014>{{cite journal|last1=Zhang|first1=Fuzhen|title=A matrix decomposition and its applications|journal=Linear and Multilinear Algebra|volume=63|issue=10|date=30 June 2014|pages=2033–2042|doi=10.1080/03081087.2014.933219|s2cid=19437967 |url=https://zenodo.org/record/851661}}</ref><ref>{{cite journal|last1=Drury|first1=S.W.|title=Fischer determinantal inequalities and Highamʼs Conjecture|journal=Linear Algebra and Its Applications|date=November 2013|volume=439|issue=10|pages=3129–3133|doi=10.1016/j.laa.2013.08.031|doi-access=free}}</ref>