We determine when there exists a ribbon rational homology cobordism
between two connected sums of lens spaces, i.e., one without
-handles.
In particular, we show that if an oriented rational homology sphere
admits a ribbon rational homology cobordism to a lens space, then
must be
homeomorphic to
,
up to orientation-reversal. As an application, we classify ribbon
-concordances between
connected sums of
-bridge
links. Our work builds on Lisca’s work on embeddings of linear lattices.
