Outer space for untwisted automorphisms of right-angled Artin groups

Ruth Charney, Nathaniel Stambaugh, Karen Vogtmann

For a right-angled Artin group $A_{\Gamma }$, the untwisted outer automorphism group $U(A_{\Gamma })$ is the subgroup of $Out(A_{\Gamma })$ generated by all of the Laurence-Servatius generators except twi…