Konstantinos Tsouvalas

activity

20192026

most citedTopological restrictions on Anosov representations

19 citations · 23 across the 18 of their papers we have counts for

collaborators

23 papers

math.GR2026

Nonarchimedean discrete groups and quasi-isometric doubles of free groups

Konstantinos Tsouvalas

For any nonarchimedean local field $k$ , we exhibit the first examples of Zariski-dense, discrete subgroups of special linear groups over $k$ , which are not commensurable to any lat…

math.GT2026

On topologically transitive subsets of flag manifolds

Subhadip Dey, Sami Douba, Konstantinos Tsouvalas

We discuss some contexts in which the topological dynamics of certain Anosov subgroups of higher-rank Lie groups on "bad" subsets of flag manifolds can be analyzed using results fr…

math.GR2026

On transversality in flag manifolds and linearity of amalgams

Sami Douba, Konstantinos Tsouvalas

We show that the fundamental group of the double of a complete negatively curved locally symmetric manifold along a closed geodesic is linear. More generally, we establish linearit…

math.GR2026

Directional growth of coamenable normal subgroups: counterexamples and rigidity

Subhadip Dey, Hee Oh, Konstantinos Tsouvalas

Roblin's theorem asserts that, in rank one, a coamenable normal subgroup has the same critical exponent as its ambient group. Natural higher-rank analogues would predict that coame…

math.GR2026

Robust quasi-isometric embeddings of virtually free groups

Konstantinos Tsouvalas

Let $k$ be a nonarchimedean local field. For any $n \geq 3$ , we construct the first examples of robust quasi-isometric embeddings of non-elementary free groups into $\mathsf{GL}_n(k…

math.GR2026

Matrix entries, unipotents, and linearity of amalgams

Sami Douba, Konstantinos Tsouvalas

We investigate linearity of amalgams of subgroups of algebraic groups along intersections with algebraic subgroups. In the process, we establish linearity of certain "doubles" of l…

math.GR2025

Undecidability of epimorphisms onto products of hyperbolic groups

Konstantinos Tsouvalas

We exhibit examples of finitely presented subgroups $P$ of direct products of hyperbolic groups for which there is no algorithm that detects whether a finitely presented group has…

math.GR2025

Ping-pong in the projective plane over a nonarchimedean field

Sami Douba, Dmitry Kubrak, Konstantinos Tsouvalas

We show that any lattice in $SL_{3} (k)$ , where $k$ is a nonarchimedean local field, contains an undistorted subgroup isomorphic to the free product $Z^{2} * Z$ …

math.GR2025

Anosov representations of amalgams

Subhadip Dey, Konstantinos Tsouvalas

For uniform lattices $Γ$ in rank 1 Lie groups, we construct Anosov representations of virtual doubles of $Γ$ along certain quasiconvex subgroups. We also show that virtual HNN exte…

math.GR2024

Subgroups of CAT(0) groups, exotic finiteness properties and non-QI-embeddings into linear groups

Claudio Llosa Isenrich, Konstantinos Tsouvalas

For every positive integer $n$ we construct an example of a subgroup $L < G$ of a linear $CAT (0)$ group $G$ such that $L$ is of finiteness type $F_{n - 1}$ and not $\m…

math.GR2024

Singular value gap estimates for free products of semigroups

Konstantinos Tsouvalas, Theodore Weisman

We establish lower estimates for singular value gaps of free products of $1$ -divergent semigroups $Γ_{1}, Γ_{2} \subset GL_{d} (K)$ which are in ping-pong position. As an…

math.GR2024

Robust quasi-isometric embeddings inapproximable by Anosov representations

Konstantinos Tsouvalas

Let $K = R$ or $C$ . For all but finitely many $m \in N$ , we exhibit the first examples of non-locally rigid, Zariski dense, robust quasi-isometric…

math.GR2024

Topological restrictions on relatively Anosov representations

Konstantinos Tsouvalas, Feng Zhu

We obtain restrictions on which groups can admit relatively Anosov representations into specified target Lie groups, by examining the topology of possible Bowditch boundaries and h…

math.GR2023

On regular subgroups of $SL_{3} (R)$

Sami Douba, Konstantinos Tsouvalas

Motivated by a question of M. Kapovich, we show that the $Z^{2}$ subgroups of $SL_{3} (R)$ that are regular in the language of Kapovich--Leeb--Porti, or diver…

math.DS2023

The Hölder exponent of Anosov limit maps

Konstantinos Tsouvalas

Let $Γ$ be a non-elementary word hyperbolic group and $d_{a}, a > 1,$ a visual metric on its Gromov boundary $\partial_{\infty} Γ$ . For an $1$ -Anosov representation $ρ:Γ\rightarrow \m…

math.GT2023★ 2 cited

On projective Anosov subgroups of symplectic groups

Maria Beatrice Pozzetti, Konstantinos Tsouvalas

We prove that a word hyperbolic group whose Gromov boundary properly contains a $2$ -sphere cannot admit a projective Anosov representation into $Sp_{2 m} (C)$ , $m\i…

math.GR2022

Anosov groups that are indiscrete in rank one

Sami Douba, Konstantinos Tsouvalas

We exhibit Anosov subgroups of $SL_{d} (R)$ that do not embed discretely in any rank- $1$ simple Lie group of noncompact type, or indeed, in any finite product of suc…

math.GR2022

Cartan projections of fiber products and non quasi-isometric embeddings

Konstantinos Tsouvalas

Let $Γ$ be a finitely generated group and $N$ be a normal subgroup of $Γ$ . The fiber product of $Γ$ with respect to $N$ is the subgroup $Γ \times_{N} Γ = {(γ, γ w) : γ \in Γ, w \in N}$ o…

math.GR2021

Fiber products of rank 1 superrigid lattices and quasi-isometric embeddings

Konstantinos Tsouvalas

Let $Δ$ be a cocompact lattice in $Sp (m, 1)$ , $m \geq 2$ , or $F_{4}^{(- 20)}$ . We exhibit examples of finitely generated subgroups of $Δ \times Δ$ with positive first Betti n…

math.GT2020★ 2 cited

Anosov representations, strongly convex cocompact groups and weak eigenvalue gaps

Konstantinos Tsouvalas

We provide characterizations of Anosov representations of word hyperbolic groups into real semisimple Lie groups in terms of the existence of equivariant limit maps on the Gromov b…

math.GT2020

Quasi-isometric embeddings inapproximable by Anosov representations

Konstantinos Tsouvalas

We construct examples of quasi-isometric embeddings of word hyperbolic groups into $SL (d, R)$ for $d ⩾ 5$ which are not limits of Anosov representations in…

math.GT2019

On Borel Anosov representations in even dimensions

Konstantinos Tsouvalas

We prove that a word hyperbolic group which admits a $P_{2 q + 1}$ -Anosov representation into $PGL (4 q + 2, R)$ contains a finite-index subgroup which is either free or…

math.GT2019★ 19 cited

Topological restrictions on Anosov representations

Richard Canary, Konstantinos Tsouvalas

We characterize groups admitting Anosov representations into $SL (3, R)$ , projective Anosov representations into $SL (4, R)$ , and Borel Anosov represe…

Nonarchimedean discrete groups and quasi-isometric doubles of free groups

On topologically transitive subsets of flag manifolds

On transversality in flag manifolds and linearity of amalgams

Directional growth of coamenable normal subgroups: counterexamples and rigidity

Robust quasi-isometric embeddings of virtually free groups

Matrix entries, unipotents, and linearity of amalgams

Undecidability of epimorphisms onto products of hyperbolic groups

Ping-pong in the projective plane over a nonarchimedean field

Anosov representations of amalgams

Subgroups of CAT(0) groups, exotic finiteness properties and non-QI-embeddings into linear groups

Singular value gap estimates for free products of semigroups

Robust quasi-isometric embeddings inapproximable by Anosov representations

Topological restrictions on relatively Anosov representations

On regular subgroups of SL3​(R)

The Hölder exponent of Anosov limit maps

On projective Anosov subgroups of symplectic groups

Anosov groups that are indiscrete in rank one

Cartan projections of fiber products and non quasi-isometric embeddings

Fiber products of rank 1 superrigid lattices and quasi-isometric embeddings

Anosov representations, strongly convex cocompact groups and weak eigenvalue gaps

Quasi-isometric embeddings inapproximable by Anosov representations

On Borel Anosov representations in even dimensions

Topological restrictions on Anosov representations

On regular subgroups of $SL_{3} (R)$