Isomorphisms Between Certain Function Fields Over Compact Riemann Surfaces.
Koebe's general uniformisation theorem for planar Riemann surfaces
We give a complete and transparent proof of Koebe's General Uniformisation Theorem that every planar Riemann surface is biholomorphic to a domain in the Riemann sphere ℂ̂, by showing that a domain with analytic boundary and at least two boundary components on a planar Riemann surface is biholomorphic to a circular-slit annulus in ℂ.
Konforme Verheftung von Gebieten mit beschränkter Randdrehung.
Konstruktion von Zahl- und Funktionenkörpern mit vorgegebener Galoisgruppe.
Leftings of Möbius groups to matrix groups.
Lengths of geodesics on Riemann surfaces with boundary.
Lifting di-analytic involutions of compact Klein surfaces to extended-Schottky uniformizations
Let S be a compact Klein surface together with a di-analytic involution κ: S → S. The lowest uniformizations of S are those whose deck group is an extended-Schottky group, that is, an extended Kleinian group whose orientation preserving half is a Schottky group. If S is a bordered compact Klein surface, then it is well known that κ can be lifted with respect to a suitable extended-Schottky uniformization of S. In this paper, we complete the above lifting property by proving that if S is a closed...
Matrices for Fenchel-Nielsen coordinates.
Maximal groups of automorphisms of compact Riemann surfaces in various classes of finite groups.
Maximal real Schottky groups.
Let S be a real closed Riemann surfaces together a reflection τ : S ---> S, that is, an anticonformal involution with fixed points. A well known fact due to C. L. May asserts that the group K(S, τ), consisting on all automorphisms ...
Metabelian groups acting on compact Riemann surfaces.
A metabelian group G acting as automorphism group on a compact Riemann surface of genus g ≥ 2 has order less than or equal to 16(g-1). We calculate for which values of g this bound is achieved and on these cases we calculate a presentation of the group G.
Moduli spaces of abelian differentials : the principal boundary, counting problems, and the Siegel-Veech constants
A holomorphic 1-form on a compact Riemann surface S naturally defines a flat metric on S with cone-type singularities. We present the following surprising phenomenon: having found a geodesic segment (saddle connection) joining a pair of conical points one can find with a nonzero probability another saddle connection on S having the same direction and the same length as the initial one. A similar phenomenon is valid for the families of parallel closed geodesics. We give a complete description of...
Modulräume stabiler 2-Bündel auf Regelflächen.
Multiple prime covers of the riemann sphere
A compact Riemann surface X of genus g≥2 which admits a cyclic group of automorphisms C q of prime order q such that X/C q has genus 0 is called a cyclic q-gonal surface. If a q-gonal surface X is also p-gonal for some prime p≠q, then X is called a multiple prime surface. In this paper, we classify all multiple prime surfaces. A consequence of this classification is a proof of the fact that a cyclic q-gonal surface can be cyclic p-gonal for at most one other prime p.
Multiply quasiplatonic Riemann surfaces.
Myrberg's numerical uniformization of hyperelliptic curves.
Non-Hyperelliptic Weierstrass Points of Maximal Weight.
Non-maximal cyclic group actions on compact Riemann surfaces.
We say that a finite group G of automorphisms of a Riemann surface X is non-maximal in genus g if (i) G acts as a group of automorphisms of some compact Riemann surface Xg of genus g and (ii), for all such surfaces Xg , |Aut Xg| > |G|. In this paper we investigate the case where G is a cyclic group Cn of order n. If Cn acts on only finitely many surfaces of genus g, then we completely solve the problem of finding all such pairs (n,g).
Notes on algebraic functions.
On a Conjecture of Magnus on the Hurwitz Monodromy Group.