Which $F_3$-by-$\mathbb{Z}$s are CAT(0)?

Leo Delage

In this note we point out a mistake in theorem 4.4 of [Sam06], which states that a semidirect product $F_3{⋊}_{\varphi }\mathbb{Z}$ whose defining automorphism $\varphi$ is unipotent-polynomi…