In this article, the author studies linear operators on Banach Spaces which can be embedded into a $C_0-$semigroup.
A linear operator $T$ on a Banach space $X$ is said to be embeddable if there exists a $C_0-$semigroup $(T(t))_{t\geq 0}$ such that $T=T(1).$
I would like some recommendations on books/articles which talks about embeddable operators and talks about the importance of such operators.