collaborators

8 papers

math.GT2026

Measurable boundary maps and Patterson--Sullivan measures for non-Borel Anosov groups on the Furstenberg boundary

Dongryul M. Kim, Andrew Zimmer

In this paper we develop a theory for Patterson--Sullivan measures for non-Borel Anosov groups on the Furstenberg boundary. Previously, such a theory has been successfully develope…

math.GT2026

Vector-valued horofunction boundaries and Patterson--Sullivan measures

Dongryul M. Kim, Andrew Zimmer

In higher rank, there is a well-studied theory of Patterson--Sullivan measures supported on partial flag manifolds. However, establishing the existence and uniqueness of such measu…

math.NT2026

Igusa Stacks and the Cohomology of Shimura Varieties II

Patrick Daniels, Pol van Hoften, Dongryul Kim +1

We construct Igusa stacks for all Shimura varieties of abelian type and derive consequences for the cohomology of these Shimura varieties. As an application, we prove that the Farg…

math.DS2025

Invariant measures on the space of measured laminations for subgroups of mapping class group

Inhyeok Choi, Dongryul M. Kim

For a non-elementary subgroup of the mapping class group of a surface, we study its invariant Radon measures on the space of measured laminations, by classifying them on the recurr…

math.DS2025

Classification of horospherical invariant measures in higher rank: Teaser

Inhyeok Choi, Dongryul M. Kim

This is an expository/teaser version of [arXiv:2601.22668] for a very special case of products of spaces. We keep this on arXiv as many parts of the argument of…

math.GT2025

A note on the singularity conjecture for infinite covolume discrete subgroups

Dongryul M. Kim, Andrew Zimmer

We consider random walks on semisimple Lie groups where the support of the step distribution generates (as a group) a Zariski dense discrete subgroup of infinite covolume. When the…

math.GT2025

Rigidity for Patterson--Sullivan systems with applications to random walks and entropy rigidity

Dongryul M. Kim, Andrew Zimmer

In this paper we introduce Patterson--Sullivan systems, which consist of a group action on a compact metrizable space and a quasi-invariant measure which behaves like a classical P…

math.DS2025

Horocycles in hyperbolic 3-manifolds with round Sierpiński limit sets

Dongryul M. Kim, Minju Lee

Let M be a geometrically finite hyperbolic 3-manifold whose limit set is a round Sierpiński gasket, i.e. M is geometrically finite and acylindrical with a compact, totally geodesic…