From the works of Gompf and Donaldson, it is known that every finitely presented
group can be realized as the fundamental group of the total space of a Lefschetz
pencil. We give an alternative proof of this fact by providing the monodromy
explicitly. In the proof, we give an alternative construction of the monodromy of
Gurtas’ fibration and a lift of that to the mapping class group of a surface with two
boundary components.
Keywords
Lefschetz pencil, Lefschetz fibration, fundamental group,
mapping class group