%0 Journal Article %A Sakasai, Takuya %T Homology cylinders and the acyclic closure of a free group %J Algebraic and Geometric Topology %D 2006 %P 603-631 %V 6 %N 2 %U http://geodesic.mathdoc.fr/articles/10.2140/agt.2006.6.603/ %R 10.2140/agt.2006.6.603 %F 10_2140_agt_2006_6_603