New methods for constructing shellable simplicial complexes

نویسندگان

چکیده مقاله:

A clutter $mathcal{C}$ with vertex set $[n]$ is an antichain of subsets of $[n]$, called circuits, covering all vertices. The clutter is $d$-uniform if all of its circuits have the same cardinality $d$. If $mathbb{K}$ is a field, then there is a one-to-one correspondence between clutters on $V$ and square-free monomial ideals in $mathbb{K}[x_1,ldots,x_n]$ as follows: To each clutter $mathcal{C}$ we correspond its circuit ideal $I(mathcal{C})$ generated by monomials $x_{i_1}cdots x_{i_k}$ with ${i_1,ldots,i_k}inmathcal{C}$. Conversely, to each square-free monomial ideal $I$ with minimal set of generators $mathcal{G}(I)$, we correspond a clutter with circuits ${i_1,ldots,i_k}$, where $x_{i_1}cdots x_{i_k}inmathcal{G}(I)$. The independence complex of a clutter $mathcal{C}$ on $[n]$ is the simplicial complex $Delta_{mathcal{C}}$ whose faces are independent sets in $mathcal{C}$ by which we mean sets $Fsubseteq [n]$ such that $ensubseteq F$ for all $einmathcal{C}$. It is easy to see that the Stanley-Reisner ideal of $Delta_{mathcal{C}}$ coincides with $I(mathcal{C})$. The above correspondence establishes a one-to-one correspondence between simplicial complexes and independence complex of clutters. A simplicial complex $Delta$ is shellable if there exists a total order on its facets, say $F_1  

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Constructing Simplicial Complexes over Topological Spaces

The first step in topological data analysis is often the construction of a simplicial complex. This complex approximates the lost topology of a sampled point set. Current techniques often assume that the input is embedded in a metric – often Euclidean – space, and make significant use of the underlying geometry for efficient computation. Consequently, these techniques do not extend to non-Eucli...

متن کامل

Simplicial Shellable Spheres via Combinatorial Blowups

The construction of the Bier sphere Bier(K) for a simplicial complex K is due to Bier (1992). Björner, Paffenholz, Sjöstrand and Ziegler (2005) generalize this construction to obtain a Bier poset Bier(P, I) from any bounded poset P and any proper ideal I ⊆ P . They show shellability of Bier(P, I) for the case P = Bn, the boolean lattice, and thereby obtain ‘many shellable spheres’ in the sense ...

متن کامل

Shellable complexes from multicomplexes

Suppose a group G acts properly on a simplicial complex Γ . Let l be the number of G-invariant vertices, and p1,p2, . . . , pm be the sizes of the G-orbits having size greater than 1. Then Γ must be a subcomplex of Λ = Δl−1 ∗ ∂Δp1−1 ∗ · · · ∗ ∂Δpm−1. A result of Novik gives necessary conditions on the face numbers of Cohen–Macaulay subcomplexes of Λ. We show that these conditions are also suffi...

متن کامل

Polygon Dissections Complexes Are Shellable

All dissections of a convex (mn + 2)-gons into (m + 2)-gons are facets of a simplicial complex. This complex is introduced by S. Fomin and A.V. Zelevinsky in [7]. We reprove the result of E. Tzanaki about shellability of such complex by finding a concrete shelling order. Also, we use this shelling order to find a combinatorial interpretation of h-vector and to describe the generating facets of ...

متن کامل

Constructing Simplicial Branched Covers

Izmestiev and Joswig described how to obtain a simplicial covering space (the partial unfolding) of a given simplicial complex, thus obtaining a simplicial branched cover [Adv. Geom. 3(2):191-255, 2003]. We present a large class of branched covers which can be constructed via the partial unfolding. In particular, for d ≤ 4 every closed oriented PL d-manifold is the partial unfolding of some pol...

متن کامل

Shellable Nonpure Complexes and Posets. I

The concept of shellability of complexes is generalized by deleting the requirement of purity (i.e., that all maximal faces have the same dimension). The usefulness of this level of generality was suggested by certain examples coming from the theory of subspace arrangements. We develop several of the basic properties of the concept of nonpure shellability. Doubly indexed f -vectors and h-vector...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


عنوان ژورنال

دوره 8  شماره 4

صفحات  0- 0

تاریخ انتشار 2022-12

با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.

کلمات کلیدی

کلمات کلیدی برای این مقاله ارائه نشده است

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023