Departmental Colloquium
Sergei Starchenko
University of Notre Dame
The topological closure of algebraic and semi-algebraic flows on complex and real tori (joint work with Y.~Peterzil)
Abstract: Let $A$ be a complex abelian variety and $\pi\colon \mathbb{C}^n\to A$
be the covering map.
It follows from a theorem of Ax that for an irreducible subvariety
$X\subseteq \mathbb{C}^n$ the Zariski closure of $\pi(X)$ is a coset
of an algebraic subgroup of $A$.
In this talk we consider \emph{the topological closure} $\pi(X)$ of an
algebraic subvariety $X$ of $\mathbb{C}^n$ and describe it in terms of
finitely many algebraic families of cosets of real subtori.
We also obtain a similar description when $A$ is a real torus and
$X$ is a semi-algebraic set.
Friday October 27, 2017 at 3:00 PM in SEO 636