Prime arithmetic Teichmuller discs in H(2)

Algebraic models and arithmetic geometry of Teichmüller curves in genus two

A Teichmüller curve is an algebraic and isometric immersion of an algebraic curve into the moduli space of Riemann surfaces. We give the first explicit algebraic models of Teichmüller curves of positive genus. Our methods are based on the study of certain Hilbert modular forms and the use of Ahlfors's variational formula to identify eigenforms for real multiplication on genus two Jacobians. We also present evidence that Teichmüller curves admit a rich arithmetic geometry by exhibiting examples with small primes of bad reduction and notable divisors supported at their cusps.

通过短曲线确定曲面及其应用

Determining surfaces by short curves and applications

本文通过短曲线参数化Teichmuller空间，证明了半算术双曲曲面在模空间中的分布定量结果，包括覆盖距离的多项式界和数量的超指数上界。

亏格2的Teichmüller曲线的极小双曲面积

Minimal Hyperbolic Area of Teichmuller Curves in Genus Two

该研究确定亏格2的Teichmüller曲线的极小双曲面积为3π/5，明确其取得条件，通过结合轨形分类与仿射下降构造，排除非平方零点模式完成证明。

Orbifold points on Prym-Teichmüller curves in genus three

Prym-Teichmüller curves $W_D(4)$ constitute the main examples of known primitive Teichmüller curves in the moduli space $\mathcal{M}_3$. We determine, for each non-square discriminant $D>1$, the number and type of orbifold points in $W_D(4)$. These results, together with the formulas of Lanneau-Nguyen and Möller for the number of cusps and the Euler characteristic, complete the topological characterisation of Prym-Teichmüller curves in genus 3. Crucial for the determination of the orbifold points is the analysis of families of genus 3 cyclic covers of degree $4$ and $6$, branched over four poi…

Orbifold points on Prym-Teichmüller curves in genus four

For each discriminant $D>1$, McMullen constructed the Prym-Teichmüller curves $W_D(4)$ and $W_D(6)$ in $\mathcal{M}_{3}$ and $\mathcal{M}_{4}$, which constitute one of the few known infinite families of geometrically primitive Teichmüller curves. In the present paper, we determine for each $D$ the number and type of orbifold points on $W_D(6)$. These results, together with a previous result of the two authors in the genus $3$ case and with results of Lanneau-Nguyen and Möller, complete the topological characterisation of all Prym-Teichmüller curves and determine their genus. The study of orbif…

New non-arithmetic complex hyperbolic lattices II

We describe a general procedure to produce fundamental domains for complex hyperbolic triangle groups, a class of groups that contains a representative of the commensurability class of every known non-arithmetic lattice in ${\rm PU}(2,1)$. We discuss several commensurability invariants for lattices, and show that some triangle groups yield new commensurability classes, bringing the number of known non-arithmetic commensurability classes to 22.