A “dead end” in the Cayley graph of a finitely generated group is an element
beyond which no geodesic ray issuing from the identity can be extended.
We study the so-called “strong dead-end depth” of group elements and its
relationship with the set of infinite quasigeodesic rays issuing from the identity. We
show that the ratio of strong depth to word length is bounded above by
in every finitely generated group and that for any element
in a finitely generated
group
, there is an
infinite
-quasigeodesic
ray issuing from the identity and passing through
.
Applying the Švarc–Milnor lemma to a finitely generated group acting geometrically
on a geodesically connected metric space, we obtain the result that for any two points
in such a space, there is an infinite quasigeodesic ray starting at one and passing
through the other with quasigeodesic constants independent of the points
selected.