For example with the code below:
\begin{bmatrix}
\mathbf{P}^-_{k} & \mathbf{C}_k\\
\mathbf{C}_k & \mathbf{S}_k
\end{bmatrix}
you will get a result looking like this:
It is apparent that those subscripts k in the matrix are not aligned both horizontally and vertically
How to properly align those subscripts in bmatrix environment?
Or are there any other matrix environments could cope with this well?
^{}
to the entries that have no superscript. About the horizontal alignment, I'm not seeing it's necessary, as all the terms have different widths..