Projective modules over the real algebraic sphere of dimension 3
Let A be a commutative noetherian ring of Krull dimension 3. We give a necessary and sufficient condition for A-projective modules of rank 2 to be free. Using this, we show that all the finitely generated projective modules over the algebraic real 3-sphere are free. (C) 2010 Elsevier Inc. All rights reserved.