Videos

Hot Topics: Interactions between Harmonic Analysis, Homogeneous Dynamics, and Number Theory: Triangle groups: From Hilbert modular varieties to complex dynamics

Presenter
March 7, 2025
Keywords:
  • Projection theorems
  • Unipotent flows
  • Effective equidistribution
  • Diophantine approximation
  • decoupling theory
MSC:
  • 11F66 - Langlands $L$L-functions one variable Dirichlet series and functional equations
  • 11J83 - Metric theory
  • 22E30 - Analysis on real and complex Lie groups [See also 33C80 43-XX]
  • 28A80 - Fractals [See also 37Fxx]
  • 37A17 - Homogeneous flows [See also 22Fxx]
  • 37C85 - Dynamics induced by group actions other than $\mathbb{Z}$\mathbb{Z} and $\mathbb{R}$\mathbb{R} and $\mathbb{C}$\mathbb{C} [See mainly 22Fxx and also 32M25 57R30 57Sxx]
  • 42B15 - Multipliers for harmonic analysis in several variables
  • 42B20 - Singular and oscillatory integrals (Calderón-Zygmund
  • etc.)
Abstract
We will discuss the reflection groups associated to hyperbolic triangles from a variety of perspectives: the arithmetic of their cusps; totally geodesic curves on Hilbert modular surfaces; and Minkowski's question mark function. The latter arises when triangle groups are mated with polynomials, to produce fractals and dynamical systems on the Riemann sphere.