H. Cunha

collaborators

3 papers

math.DG2024

Gears and pulleys in non-Euclidean space forms

Heleno S. Cunha, Lucas H. R. de Souza, Sergio A. P. Prado

In this article we study, in their non-Euclidean versions, two important mechanical systems that are very common in numerous devices. More precisely, we study the laws governing th…

math.DG2013

A note on trace fields of complex hyperbolic groups

Heleno Cunha, Nikolay Gusevskii

We show that if $Γ$ is an irreducible subgroup of $SU (2, 1)$ , then $Γ$ contains a loxodromic element $A$ . If $A$ has eigenvalues $λ_{1} = λ e^{i φ},$ $λ_{2} = e^{- 2 i φ}$ , $λ_3 = λ^{-…

math.GT2008

On the moduli space of quadruples of points in the boundary of complex hyperbolic space

Heleno Cunha, Nikolay Gusevskii

We consider the space $M$ of ordered quadruples of distinct points in the boundary of complex hyperbolic $n$ -space, $ch n,$ up to its holomorphic isometry group ${\rm PU…