f - vectors of simplicial posets that are balls
نویسنده
چکیده
Results of R. Stanley and M. Masuda completely characterize the hvectors of simplicial posets whose order complexes are spheres. In this paper we examine the corresponding question in the case where the order complex is a ball. Using the face rings of these posets, we develop a series of new conditions on their h-vectors. We also present new methods for constructing poset balls with specific h-vectors. Combining this work with a new result of S. Murai we are able to give a complete characterization of the h-vectors of simplicial poset balls in all even dimensions, as well as odd dimensions less than or equal to five.
منابع مشابه
f-vectors and h-vectors of simplicial posets
Stanely, R.P., f-vectors and h-vectors of simplicial posets, Journal of Pure and Applied Algebra 71 (1991) 319-331. A simplicial poset is a (finite) poset P with d such that every interval [6, x] is a boolean algebra. Simplicial posets are generalizations of simplicial complexes. The f-vector f(P) = (f,, f,, , ,f_,) of a simplicial poset P of rank d is defined by f; = #{x E P: [6, x] g B,, I}, ...
متن کاملGenocchi numbers and f-vectors of simplicial balls
The aim of this note is to investigate f -vectors of simplicial balls, especially the relations between interior and boundary faces. For a simplicial ball B we denote by fi(B) the number of i-dimensional faces. The boundary ∂B of B is a simplicial sphere with face numbers fi(∂B). We also define fi(int B) := fi(B) − fi(∂B) although the interior int B of B is not a polyhedral complex. For simplic...
متن کاملLinear Inequalities for Enumerating Chains in Partially Ordered Sets
We characterize the linear inequalities satisfied by flag f -vectors of all finite bounded posets. We do the same for semipure posets. In particular, the closed convex cone generated by flag f -vectors of bounded posets of fixed rank is shown to be simplicial, and the closed cone generated by flag f -vectors of semipure posets of fixed rank is shown to be polyhedral. The extreme rays of both of...
متن کاملA classification of the face numbers of Buchsbaum simplicial posets
The family of Buchsbaum simplicial posets generalizes the family of simplicial cell manifolds. The h′vector of a simplicial complex or simplicial poset encodes the combinatorial and topological data of its face numbers and the reduced Betti numbers of its geometric realization. Novik and Swartz showed that the h′-vector of a Buchsbaum simplicial poset satisfies certain simple inequalities. In t...
متن کاملSUBDIVISIONS AND LOCAL h-VECTORS
In Part I a general theory of f-vectors of simplicial subdivisions (ortriangulations) of simplicial complexes is developed, based on the concept of lo-cal h-vector. As an application, we prove that the h-vector of a Cohen-Macaulaycomplex increases under "quasi-geometric" subdivision, thus establishing a spe-cial case of a conjecture of Kalai and this author. Techniques include c...
متن کامل