All Questions

Let $R$ be a commutative ring with unit. Let $M_A$ denote the submodule of $R^m$ generated by columns of a matrix $A$ with entries in $R$. Suppose we are given two matrices $A,B \in R^{m \times k}$. I ...

Let $\text{M}_n(R)$ be the ring of $n$-by-$n$ matrices with entries in a commutative unital ring $R$. Theorem III in C.R. Yohe, Triangular and Diagonal Forms for Matrices over Commutative ...

let $k$ be a field, and let $A$ be a central simple $k$-algebra over $k$. What is the maximal dimension of a commutative $k$-subalgebra of $A$? If $A=M_r(D)$, where $D$ is a central division $k$-...