Let $A\in \mathbb{C}^{ n\times n}$ and $B \in \mathbb{C}^{p \times p}$ be a Hermitian matrix then find amatrices with $p < n$.
Find matrix $X$ such that $X^*AX=B$ where$X^*AX=B.$
Solution in the case of positive definite $B \in \mathbb{C}^{p \times p}$ is a given Hermitian matrix$A$ and $p< n$$B$ was given here.