How can I write a big matrix (or array) in the width of the page while using two columns for all paper? I know that for figures (
figure*) can be used, is there any way to do it for arrays?
You can't switch from
twocolumn mode to
onecolumn mode in the middle of the page. The only mechanism is using the environment
If you need such a switch you can work with the great package
Frank Mittelbach answered a similar question some time ago: