Modultheorie hyperelliptischer Mumfordkurven.
We discuss a common framework for studying twists of Riemann surfaces coming from earthquakes, Teichmüller theory and Schiffer variations, and use it to analyze geodesics in the moduli space of isoperiodic 1-forms.
We give an explicit description of a non-normal irreducible subvariety of the moduli space of Riemann surfaces of genus 3 characterized by a non-cyclic group action. Defining equations of a family of curves representing non-normal points of this subvariety are computed. We also find defining equations of the family of hyperelliptic curves of genus 3 whose full automorphism group is C2 X C4. This completes the list of full automorphism groups of hyperelliptic curves.
Let Σ be a closed oriented Riemann surface of genus at least 2. By using symplectic chain complex, we construct a volume element for a Hitchin component of Hom(π₁(Σ),PSLₙ(ℝ))/PSLₙ(ℝ) for n > 2.