The Width of Extraspecial Unipotent Radical with Respect to a Set of Root Elements

详细

Let G = G(Φ,K) be a Chevalley group of type Φ over a field K, where Φ is a simply laced root system. By studying the extraspecial unipotent radical of G, it is proved that any its element is a product of at most three root elements. Moreover, it is shown that up to conjugation by an element of the Levi subgroup, any element of the radical is the product of six elementary root elements.