Abstract
We show that the γ-vector of the order complex of any polytope is the f-vector of a balanced simplicial complex. This is done by proving this statement for a subclass of Stanley's S-shellable CW-spheres which includes all polytopes. The proof shows that certain parts of the cd-index, when specializing c = 1 and considering the resulted polynomial in d, are the f-polynomials of simplicial complexes that can be colored with "few" colors. We conjecture that the cd-index of a regular CW-sphere is itself the flag f-vector of a colored simplicial complex in a certain sense.
Original language | English |
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Pages (from-to) | 1309-1319 |
Number of pages | 11 |
Journal | Mathematische Zeitschrift |
Volume | 271 |
Issue number | 3-4 |
DOIs | |
State | Published - Aug 2012 |
Externally published | Yes |
Bibliographical note
Funding Information:Research of the first author was partially supported by KAKENHI 22740018. Research of the second author was partially supported by an NSF Award DMS-0757828 and Marie Curie grant IRG-270923.
Keywords
- Balanced simplicial complex
- Polytope
- cd-index
- γ-vector