The cd-index of fans and lattices
Algebraic Geometry
2007-05-23 v2 Combinatorics
Abstract
The number of flags in a complete fan, or more generally in an Eulerian poset, is encoded in the cd-index. We prove non-negativity of the cd-index for complete fans, regular CW-spheres and Gorenstein* posets.
Cite
@article{arxiv.math/0410513,
title = {The cd-index of fans and lattices},
author = {Kalle Karu},
journal= {arXiv preprint arXiv:math/0410513},
year = {2007}
}
Comments
The difference between lattices and posets clarified. 19 pages