International Journal of Mathematics and Mathematical Sciences
Volume 3 (1980), Issue 4, Pages 719-730
doi:10.1155/S016117128000052X
Extensions of group retractions
Richard D. Byrd
, Justin T. Lloyd
, Roberto A. Mena
and J.Roger Teller
Department of Mathematics, University of Houston, Houston 77004, Texas, USA
Abstract
In this paper a condition, which is necessary and sufficient, is determined when a retraction of a subgroup H of a torsion-free group G can be extended to a retraction of G. It is also shown that each retraction of a torsion-free abelian group can be uniquely extended to a retraction of its divisible closure.