We show that sufficiently irreducible Anosov actions of higher rank abelian groups on tori and nilmanifolds are C ∞-conjugate to affine actions.
Ultrasound imaging was used to investigate the articulation of the voiceless velar stop [k] in five speakers with compensatory articulation related to cleft palate. The perceptual evaluation of the acoustic realization and the visual assessment of the tongue movement for the target sound were made by three examiners. The analysis revealed a variety of… (More)
In this article we survey recent progress on quasi-isometric rigidity of polycyclic groups. These results are contributions to Gromov's program for classifying finitely generated groups up to quasi-isometry [Gr2]. The results discussed here rely on a new technique for studying quasi-isometries of finitely generated groups, which we refer to as coarse… (More)