I want to compute the inverse of the $2\times2$ block matrix $$ \left(\begin{array}{cc} A & P\\ P^T & 0\\ \end{array}\right), $$ with $A$ an $n\times{n}$ matrix and $P$ and $n\times{m}$ matrix.

I only come across formulas for $$ \left(\begin{array}{cc} A & B\\ C & D\\ \end{array}\right)^{-1} $$ that involve $D^{-1}$. However, in my case $D=0$, such that $D$ has no inverse and I don't know how to continue.


One of the formulas here does not involve $D^{-1}$

  • 1
    $\begingroup$ Thanks, I just found it myself as well. Wanted to say just that when I saw your answer. I started searching in papers - guess I should trust Wikipedia more often :p $\endgroup$ – Eric S. Mar 1 '16 at 14:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.