  In this paper, we consider a time-periodically forced Kepler problem in any
dimensions, with an external force which we only assume to be regular in a
neighborhood of the attractive center. We prove that there exist infinitely
many periodic orbits in this system, with possible double collisions with the
center regularized, which accumulate the attractive center. The result is
obtained via a localization argument combined with a result on
$C^{1}$-persistence of closed orbits by a local homotopy-streching argument.
Consequently, by formulating the circular and elliptic restricted three-body
problems of any dimensions as time-periodically forced Kepler problems, we
obtain that there exists infinitely many periodic orbits, with possible double
collisions with the primaries regularized, accumulating to each of the
primaries.
