5 papers
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…
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…
Quasihomomorphisms to real algebraic groups
Sami Douba, Francesco Fournier-Facio, Sam Hughes +1
A quasihomomorphism is a map that satisfies the homomorphism relation up to bounded error. Fujiwara and Kapovich proved a rigidity result for quasihomomorphisms taking values in di…
Ping-pong in the projective plane over a nonarchimedean field
Sami Douba, Dmitry Kubrak, Konstantinos Tsouvalas
We show that any lattice in , where is a nonarchimedean local field, contains an undistorted subgroup isomorphic to the free product …
Zariski-Closures of Linear Reflection Groups
Jacques Audibert, Sami Douba, Gye-Seon Lee +1
We give necessary and sufficient conditions for a linear reflection group in the sense of Vinberg to be Zariski-dense in the ambient projective general linear group. As an applicat…