2016/07/19 by Zheng, Hailun · 1 citation
#Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.1607.05757
We characterize homology manifolds with g2≤ 2. Specifically, using retriangulations of simplicial complexes, we give a short proof of Nevo and Novinsky's result on the characterization of homology (d-1)-spheres with g2=1 for d≥ 5 and extend it to the class of normal pseudomanifolds. We proceed to prove that every prime homology manifold with g2=2 is obtained by centrally retriangulating a polytopal sphere with g2≤ 1 along a certain subcomplex. This implies that all homology manifolds with g2=2 are polytopal spheres.