Abstract
We present an explicit structure for the Baer invariant of a finitely generated abelian group with respect to the variety [๐ c 1 , ๐ c 2 ], for all c 2 โค c 1 โค 2c 2. As a consequence, we determine necessary and sufficient conditions for such groups to be [๐ c 1 , ๐ c 2 ]-capable. We also show that if c 1 โ 1 โ c 2, then a finitely generated abelian group is [๐ c 1 , ๐ c 2 ]-capable if and only if it is capable. Finally, we show that ๐2-capability implies capability, but there is a capable finitely generated abelian group which is not ๐2-capable.
ACKNOWLEDGMENT
The first author was in part supported by a grant from IPM No. 85200018.
Notes
Communicated by A. Olshanskii.