We develop a geometric approach to the study of plane sextics with a triple singular
point. As an application, we give an explicit geometric description of all irreducible
maximal sextics with a type E7 singular point and compute their fundamental
groups. All groups found are finite; one of them is nonabelian.
Keywords
plane sextic, fundamental group, trigonal
curve, dessin d'enfant
Received: 22 December 2008
Revised: 2 October 2009
Accepted: 28 September 2009
Preview posted: 29 October 2009
Published: 2 January 2010
Proposed: Joan Birman
Seconded: Simon Donaldson, Walter Neumann