Abstract:
In the paper, Problem 18.3 of the book “Abelian
groups” (2015) by L. Fuchs is solved in the case of Abelian groups with finite
$p$-ranks.
For an Abelian group $A$,
a sequence of groups $(A_n)$
is
considered, where
$A_0=A$
and $A_{n+1}=\operatorname{End}A_n$.
It is shown
that, if all
$p$-ranks of the group $A$
are finite, then this sequence can
stabilize either after
$A_0$
or after $A_1$.