10 citations · 26 across the 11 of their papers we have counts for
7 papers · 1 filter
Real representations of semisimple Lie algebras have Q-forms
Dave Witte
We prove that each real semisimple Lie algebra G has a Q-form, such that every real representation of G can be realized over the rational numbers Q. This was previously proved by M…
Superrigid subgroups and syndetic hulls in solvable Lie groups
Dave Witte
This is an expository paper. It is not difficult to see that every group homomorphism from the additive group Z of integers to the additive group R of real numbers extends to a hom…
Cartan-decomposition subgroups of SU(2,n)
Alessandra Iozzi, Dave Witte
We give explicit, practical conditions that determine whether or not a closed, connected subgroup H of G = SU(2,n) has the property that there exists a compact subset C of G with C…
Archimedean superrigidity of solvable S-arithmetic groups
Dave Witte
Let $\Ga$ be a connected, solvable linear algebraic group over a number field~, let be a finite set of places of~ that contains all the infinite places, and let $\theints…
Correction to "Zero-entropy affine maps on homogeneous spaces
Dave Witte
Proposition~6.4 of the author's paper {\origpaper} is incorrect. This invalid proposition was used in the proof of Corollary~6.5, so we provide a new proof of the latter result.
Cocycle superrigidity for ergodic actions of non-semisimple Lie groups
Dave Witte
Suppose is a semisimple Levi subgroup of a connected Lie group~, is a Borel -space with finite invariant measure, and $α\colon X \times G \to \GL_n(\real)$ is a Borel…