On centrality of K2 for Chevalley groups of type Eℓ

Abstract For a root system Φ of type E l and arbitrary commutative ring R we show that the group K 2 ( Φ , R ) is contained in the center of the Steinberg group St ( Φ , R ) . In course of the proof we also demonstrate an analogue of Quillen–Suslin local–global principle for K 2 ( Φ , R ) .