Questions tagged [block-matrices]

For questions about matrices which are defined block wise, like $\pmatrix{A&B\ C&D}$ where $A,B,C$ and $D$ are themselves matrices. Use this tag with (matrices), and often with (linear-algebra).

908 questions
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Subset of $GL(n,R)$

I'm trying to understand why the subset of $GL(n,\mathbb{R})$ formed by the block-matrices of the following type: $$\begin{pmatrix} A & B \\ 0 & C \end{pmatrix}$$ where $$A \in GL(k,\mathbb{R}),~ C \in GL(n-k,\mathbb{R}),~ B \in…
Br09
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when block matrix is positive definite ,

can one tell me when the block matrix M=[A B,C D] is positive definite such as: 1-the four block A,B,C and D are symmetric diagonal positive definite matrices 2-M is asymmetric, so C is not the transpose of B, and we can not apply schur formula
fidel
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Characteristic polynomial of triangular blocks matrix

Let A be a triangular blocks matrix (the blocks are: A1,...,Ak). Show that CA(t)=CA1(t)*...*CAk(t). Any help ? thanks ;) (edit: CA and CAj are the characteristic polynomials of the blocks)
Jenni201
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Product of the off-diagonal block matrices

Consider two real symmetric positive matrices $A\geq0$ and $B\geq 0$ with the following block form \begin{equation} A= \begin{pmatrix}\begin{array}{@{}c|c@{}} A_{11} & A_{12} \\ \hline A_{21} & A_{22} \\ \end{array}\end{pmatrix}, \quad…
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Determinant and Inverse of a block matrix with diagonal blocks

So I want to calculate the inverse and determinant of a block matrix ($n\times n$) with diagonal matrices (of same size) as block. Although I have a general idea as to how to calculate the determinant. I can't find anything relevant to find the…