2012/03/08 by Murai, Satoshi, Nevo, Eran · 1 citation
#13F55 #52B05 #Combinatorics (math.CO) #Commutative Algebra (math.AC) #FOS: Mathematics
paper · doi:10.48550/arxiv.1203.1720
In 1971, McMullen and Walkup posed the following conjecture, which is called the generalized lower bound conjecture: If P is a simplicial d-polytope then its h-vector (h0,h1,...,hd) satisfies h0 ≤ h1 ≤ ... ≤ h\lfloor \frac d 2 \rfloor. Moreover, if hr-1=hr for some r ≤ \frac d 2 then P can be triangulated without introducing simplices of dimension ≤ d-r. The first part of the conjecture was solved by Stanley in 1980 using the hard Lefschetz theorem for projective toric varieties. In this paper, we give a proof of the remaining part of the conjecture. In addition, we generalize this property to a certain class of simplicial spheres, namely those admitting the weak Lefschetz property.