I'm confused about the difference between a Galilean transformation and boost with reference to their matrices. I was given four statements (listed below) but I'm not sure what I should be looking for to determine their validity. Apologies if this has been answered before I could only see boost vs translation but wasn't sure if this was the same.
$ \begin{bmatrix} 1 & 0 & 0 & 0 \\ v & 1 & 0 & 1 \\ -v & 0 & 1 & 0 \\ 0 & -1 & 0 & 0 \\ \end{bmatrix} $ is a Galilean transformation
$ \begin{bmatrix} 1 & 0 & 0 & 0 \\ v & 0 & 0 & 1 \\ 0 & 0 & 1 & 0 \\ 2v & -1 & 0 & 0 \\ \end{bmatrix} $ is a Galilean transformation
$ \begin{bmatrix} 1 & 0 & 0 & 0 \\ v & 1 & 0 & 0 \\ v & 0 & 1 & 0 \\ -v & 0 & 0 & 1 \\ \end{bmatrix} $ is a Galilean boost
$ \begin{bmatrix} 1 & 0 & 0 & 0 \\ 2v & 0 & -1 & 0 \\ v & 1 & 0 & 0 \\ 2v & 0 & 0 & 1 \\ \end{bmatrix} $ is a Galilean transformation but not a Galilean boost