# Chevalley’s Theorem on constructible images made constructive

 Speaker(s) Mohamed Barakat Universität Siegen Date 30 January 2020 – 09:10 to 10:00 Venue INI Seminar Room 1 Session Title Chevalley’s Theorem on constructible images made constructive Event [GRAW02] Computational and algorithmic methods Abstract Chevalley proved that the image of an algebraic morphism between algebraic varieties is a constructible set. Examples are orbits of algebraic group actions. A constructible set in a topological space is a finite union of locally closed sets and a locally closed set is the difference of two closed subsets. Simple examples show that even if the source and target of the morphism are affine varieties the image may neither be affine nor quasi-affine. In this talk, I will present a Gröbner-basis-based algorithm that computes the constructible image of a morphism of affine spaces, along with some applications.