Definition
A matrix is a block diagonal matrix if:
c_{1}I_{d_{1}} & 0 & \dots & 0\\ 0 &c_{2} I_{d_{2}} & \dots &0\\ 0 &\dots & 0 &c_{n}I_{d_{n}} \\ \end{array}\right]$$ Where: - $I_{d_{j}}$ is the [[Identity Matrix]] of $d_{j} \times d_{j}$ - $c_{j}$ is a [[Eigenvector|Eigenvalue]] # Intuition - This is a [[Diagonal Matrices|Diagonal Matrix]] where eigenvalues can be repeated, and all repeated eigenvalues are right next to eachother