ABSTRACT
A 4 = —pi/24, As = ( —4p2 + 7pi)/5760, A l2 = (-16/* + 44PlP2 - 3lrf)/967680
where A n denotes n-dimensional component of A. We recall from lemma 2.27 how
symmetric function in the formal variables yj. The result is the expansion of the
THEOREM 13.1 (L lCHNEROW lCZ [48 ]) Let M be a compact manifold which admits
a spin structure, and for which the A-genus (A (M ), [M ]) is non-zero. Then M admits no metric of strictly positive scalar curvature.
