2011/11/20 by Stavrova, Anastasia · 2 citations
#19B99 #20G07 #20G15 #20G35 #Algebraic Geometry (math.AG) #FOS: Mathematics #Group Theory (math.GR) #K-Theory and Homology (math.KT)
paper · doi:10.48550/arxiv.1111.4664
Let G be reductive algebraic group over a field k, such that every semisimple normal subgroup of G has isotropic rank >=2. Let K1G be the non-stable K1-functor associated to G (also called the Whitehead group of G in the field case). We show that K1G(k)=K1G(k[X1,...,Xn]) for any n>= 1. This implies that K1G is A1-homotopy invariant on the category of regular k-algebras, if k is perfect. If k is infinite perfect, one also deduces that K1G(R)-> K1G(K) is injective for any regular local k-algebra R with the fraction field K.