Richard Ehrenborg ; Mark Goresky ; Margaret Readdy
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Euler flag enumeration of Whitney stratified spaces
dmtcs:12799 -
Discrete Mathematics & Theoretical Computer Science,
January 1, 2013,
DMTCS Proceedings vol. AS, 25th International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2013)
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https://doi.org/10.46298/dmtcs.12799
Euler flag enumeration of Whitney stratified spacesArticle
Authors: Richard Ehrenborg 1; Mark Goresky 2; Margaret Readdy 1
0000-0001-5854-3890##NULL##0000-0002-3648-0865
Richard Ehrenborg;Mark Goresky;Margaret Readdy
1 Department of Mathematics
2 School of Mathematics [Princeton]
We show the $\mathrm{cd}$-index exists for Whitney stratified manifolds by extending the notion of a graded poset to that of a quasi-graded poset. This is a poset endowed with an order-preserving rank function and a weighted zeta function. This allows us to generalize the classical notion of Eulerianness, and obtain a $\mathrm{cd}$-index in the quasi-graded poset arena. We also extend the semi-suspension operation to that of embedding a complex in the boundary of a higher dimensional ball and study the shelling components of the simplex.