2013/01/18 by Barbot, Thierry · 2 citations
#Differential Geometry (math.DG) #FOS: Mathematics #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Representation Theory (math.RT)
paper · doi:10.48550/arxiv.1301.4309
Let Γ be a finitely generated group, and let \opRep(Γ, \SO(2,n)) be the moduli space of representations of Γ into \SO(2,n) (n ≥ 2). An element ρ: Γ→ \SO(2,n) of \opRep(Γ, \SO(2,n)) is quasi-Fuchsian if it is faithful, discrete, preserves an acausal subset in the conformal boundary \Einn of the anti-de Sitter space; and if the associated globally hyperbolic anti-de Sitter space is spatially compact - a particular case is the case of Fuchsian representations, i.e. composition of a faithfull, discrete and cocompact representation ρf: Γ→ \SO(1,n) and the inclusion \SO(1,n) ⊂ \SO(2,n). In \citemerigot we proved that quasi-Fuchsian representations are precisely representations which are Anosov as defined in \citelabourie. In the present paper, we prove that quasi-Fuchsian representations form a connected component of \opRep(Γ, \SO(2,n)). This is an almost direct corollary of the following result: let Γ be the fundamental group of a globally hyperbolic spacetime locally modeled on \AdSn, and let ρ: Γ→ \SO0(2,n) be the holonomy representation. Then, if Γ is Gromov hyperbolic, the ρ(Γ)-invariant achronal limit set in \Einn is acausal.