Smith Normal Form of the product of a matrix with its transpose after swapping columns

83 Views Asked by At

Suppose I have an integer matrix $M$ and I consider the Smith Normal Form of the matrix $MM^T$. If I then swap two columns of $M$, does that affect the Smith Normal Form of $MM^T$?

1

There are 1 best solutions below

1
On

It does not. If $P$ is a matrix obtained by permuting the columns of $M$, then $MM^T = PP^T$. Because $MM^T$ and $PP^T$ are equal, they have the same normal form.