Non-cover generalized Mycielski, Kneser, and Schrijver graphs
نویسندگان
چکیده
منابع مشابه
Backbone Colorings and Generalized Mycielski Graphs
For a graph G and its spanning tree T the backbone chromatic number, BBC(G,T ), is defined as the minimum k such that there exists a coloring c : V (G) → {1, 2, . . . , k} satisfying |c(u) − c(v)| ≥ 1 if uv ∈ E(G) and |c(u)− c(v)| ≥ 2 if uv ∈ E(T ). Broersma et al. [1] asked whether there exists a constant c such that for every triangle-free graphG with an arbitrary spanning tree T the inequali...
متن کاملOn the diameter of generalized Kneser graphs
Let r , k be positive integers, s(< r), a nonnegative integer, and n=2r−s+k. The set of r-subsets of [n]={1, 2, . . . , n} is denoted by [n]r . The generalized Kneser graphK(n, r, s) is the graph whose vertex-set is [n]r where two r-subsets A and B are joined by an edge if |A ∩ B| s. This note determines the diameter of generalized Kneser graphs. More precisely, the diameter of K(n, r, s) is eq...
متن کاملcommuting and non -commuting graphs of finit groups
فرض کنیمg یک گروه غیر آبلی متناهی باشد . گراف جابجایی g که با نماد نمایش داده می شود ،گرافی است ساده با مجموعه رئوس که در آن دو راس با یک یال به هم وصل می شوند اگر و تنها اگر . مکمل گراف جابجایی g راگراف نا جابجایی g می نامیم.و با نماد نشان می دهیم. گرافهای جابجایی و ناجابجایی یک گروه متناهی ،اولین بار توسطاردوش1 مطرح گردید ،ولی در سالهای اخیر به طور مفصل در مورد بحث و بررسی قرار گرفتند . در ،م...
15 صفحه اولOn the Chromatic Number of Generalized Stable Kneser Graphs
For each integer triple (n, k, s) such that k ≥ 2, s ≥ 2, and n ≥ ks, define a graph in the following manner. The vertex set consists of all k-subsets S of Zn such that any two elements in S are on circular distance at least s. Two vertices form an edge if and only if they are disjoint. For the special case s = 2, we get Schrijver’s stable Kneser graph. The general construction is due to Meunie...
متن کاملColoring Reduced Kneser Graphs
The vertex set of a Kneser graph KG(m,n) consists of all n-subsets of the set [m] = {0, 1, . . . ,m − 1}. Two vertices are defined to be adjacent if they are disjoint as subsets. A subset of [m] is called 2stable if 2 ≤ |a − b| ≤ m − 2 for any distinct elements a and b in that subset. The reduced Kneser graph KG2(m,n) is the subgraph of KG(m,n) induced by vertices that are 2-stable subsets. We ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 2008
ISSN: 0012-365X
DOI: 10.1016/j.disc.2007.08.082