Pairs of symmetries of Riemann surfaces.
Parabolic bundles, elliptic surfaces and SU (2)-representation spaces of genus zero Fuchsian groups.
Plane Motion Groups and Virtual Poincaré Duality of Dimension Two.
Poincaré duality groups of dimension two.
Power subgroups of Hecke groups .
Principal congruence link complements
In this paper we study principal congruence link complements in . It is known that there are only finitely many such link complements, and we make a start on enumerating them using a combination of theoretical methods and computer calculations with MAGMA.
Proper periods of normal N.E.C. subgroups with even index.
By a non-Euclidean crystallographic (N.E.C.) group we shall mean a discrete subgroup Γ of isometries of the non-Euclidean plane including those reverse orientation, reflections and glide-reflections.In [1] we computed the proper periods of normal N.E.C. subgroups of an N.E.C. group, when the index of the group with respect to the subgroup is odd. In this paper we shall compute the proper period of normal N.E.C. subgroups, when the index is even.The corresponding problem for Fuchsian groups, which...
Propriétés générales des substitutions à une variable et des fonctions qu'elles laissent invariables