Lavrenyuk Ya. V.
Lattice of normal subgroups of a group of local isometries of the boundary of a spherically homogeneous tree
Ukr. Mat. Zh. - 2008. - 60, № 10. - pp. 1350–1356
We describe the structure of the lattice of normal subgroups of the group of local isometries of the boundary of a spherically homogeneous tree LIsom ∂T. It is proved that every normal subgroup of this group contains its commutant. We characterize the quotient group of the group LIsom ∂T by its commutant.