Complexes 6 Simplicial complex
نویسنده
چکیده
Definition 20 (simplex). A k-simplex σ is the convex hull of a set P of k + 1 affinely independent points. In particular, a 0-simplex is a vertex, a 1-simplex is an edge, a 2-simplex is a triangle, and a 3-simplex is a tetrahedron. A k-simplex is said to have dimension k. A face of σ is a simplex that is the convex hull of a nonempty subset of P. Faces of σ come in all dimensions from zero (σ’s vertices) to k; σ is a face of σ. A proper face of σ is a simplex that is the convex hull of a proper subset of P; i.e. any face except σ. In particular, the (k − 1)-faces of σ are called facets of σ; σ has k + 1 facets. For instance, the facets of a tetrahedron are its four triangular faces.
منابع مشابه
Vertex Decomposable Simplicial Complexes Associated to Path Graphs
Introduction Vertex decomposability of a simplicial complex is a combinatorial topological concept which is related to the algebraic properties of the Stanley-Reisner ring of the simplicial complex. This notion was first defined by Provan and Billera in 1980 for k-decomposable pure complexes which is known as vertex decomposable when . Later Bjorner and Wachs extended this concept to non-pure ...
متن کاملCohen-Macaulay-ness in codimension for simplicial complexes and expansion functor
In this paper we show that expansion of a Buchsbaum simplicial complex is $CM_t$, for an optimal integer $tgeq 1$. Also, by imposing extra assumptions on a $CM_t$ simplicial complex, we provethat it can be obtained from a Buchsbaum complex.
متن کاملNew methods for constructing shellable simplicial complexes
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}...
متن کاملOn a special class of Stanley-Reisner ideals
For an $n$-gon with vertices at points $1,2,cdots,n$, the Betti numbers of its suspension, the simplicial complex that involves two more vertices $n+1$ and $n+2$, is known. In this paper, with a constructive and simple proof, wegeneralize this result to find the minimal free resolution and Betti numbers of the $S$-module $S/I$ where $S=K[x_{1},cdots, x_{n}]$ and $I$ is the associated ideal to ...
متن کاملChromatic Polynomials of Simplicial Complexes
In this note we consider s-chromatic polynomials for finite simplicial complexes. When s = 1, the 1-chromatic polynomial is just the usual graph chromatic polynomial of the 1-skeleton. In general, the s-chromatic polynomial depends on the s-skeleton and its value at r is the number of (r, s)-colorings of the simplicial complex.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2017