activity
20222026
collaborators

10 papers

math.DG2026

Strict concavity of the growth indicator function for relatively Anosov groups

Dongryul M. Kim, Hee Oh, Andrew Zimmer

Let be a discrete subgroup of a connected semisimple real algebraic group of higher rank. The growth indicator function records the directional exponential growth of the…

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.CV2026

Rigidity of proper holomorphic maps between balls with Hölder boundary regularity

Kyle Huang, Jinwoo Park, Aleksander Skenderi +3

In this paper, we prove a rigidity result for proper holomorphic maps between unit balls that have many symmetries and which extend to Hölder continuous maps on the boundary, with…

math.GT2025

Determining subgroups via stationary measures

Dongryul M. Kim, Andrew Zimmer

In this paper, we consider random walks on the isometry groups of general metric spaces. Under some mild conditions, we show that if two non-elementary random walks on a discrete s…

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.CV2025

Weakly holomorphic homogeneous regular manifolds

Andrew Zimmer

We introduce a class of complex manifolds which we call weakly holomorphic homogeneous regular manifolds (wHHR) manifolds. As the name suggests, this class contains the so-called h…

math.CV2023

Smooth equivalence of families of strongly pseudoconvex domains

Hervé Gaussier, Xianghong Gong, Andrew Zimmer

We establish a smoothness result for families of biholomorphisms between smooth families of strongly pseudoconvex domains, each with trivial biholomorphism group. This is accomplis…

math.GT2022

The structure of relatively hyperbolic groups in convex real projective geometry

Mitul Islam, Andrew Zimmer

In this paper we prove a general structure theorem for relatively hyperbolic groups (with arbitrary peripheral subgroups) acting naive convex co-compactly on properly convex domain…