A Note on Link Complements and Arithmetic Groups.
A spectral proof of Rademacher's conjecture for congruence subgroups of the modular group.
A Symbolic Dynamics for Geodesics on Punctured Riemann Surfaces.
Addendum : Finiteness theorems for discrete subgroups of bounded covolume in semi-simple groups
An isomorphism between polynomial eigenfunctions of the transfer operator and the Eichler cohomology for modular groups.
Analogs of Δ(z) for triangular Shimura curves
We construct analogs of the classical Δ-function for quotients of the upper half plane 𝓗 by certain arithmetic triangle groups Γ coming from quaternion division algebras B. We also establish a relative integrality result concerning modular functions of the form Δ(αz)/Δ(z) for α in B⁺. We give two explicit examples at the end.
Arithmetic Fuchsian groups and the number of systoles.
Arithmetische Eigenschaften hyperbolischer Klassen elliptischer Modulgruppen.
Around the Borromean link.
This is a survey of some consequences of the fact that the fundamental group of the orbifold with singular set the Borromean link and isotropy cyclic of order 4 is a universal kleinian group.