We give a systematic construction of epimorphisms
between 2–bridge link groups.
Moreover, we show that 2–bridge links having
such an epimorphism between their link groups
are related by a map between the ambient spaces
which only have a certain specific kind of singularity.
We show applications of these epimorphisms
to the character varieties for 2–bridge links
and π1–dominating maps among 3–manifolds.
Dedicated to the memory of Professor
Heiner Zieschang
Keywords
2-bridge knot, knot group, character
variety, degree 1 map