منابع مشابه
The Polytope of Degree Partitions
The degree partition of a simple graph is its degree sequence rearranged in weakly decreasing order. Let DP(n) (respectively, DS(n)) denote the convex hull of all degree partitions (respectively, degree sequences) of simple graphs on the vertex set [n] = {1, 2, . . . , n}. We think of DS(n) as the symmetrization of DP(n) and DP(n) as the asymmetric part of DS(n). The polytope DS(n) is a well st...
متن کاملThe Excess Degree of a Polytope
We define the excess degree ξ(P ) of a d-polytope P as 2f1− df0, where f0 and f1 denote the number of vertices and edges, respectively. We first prove that the excess degree of a d-polytope does not take every natural number: the smallest possible values are 0 and d − 2, and the value d − 1 only occurs when d = 3 or 5. On the other hand, for fixed d , the number of values not taken by the exces...
متن کاملThe Polytope of Dual Degree Partitions
We determine the extreme points and facets of the convex hull of all dual degree partitions of simple graphs on n vertices. 1
متن کاملDegree sequences of multigraphs
Let a, b and n be integers, n ≥ 1 and b ≥ a ≥ 0. Let an (a, b, n)-graph defined as a loopless graph G(a, b, n) on n vertices {V1, . . . , Vn}, in which Vi and Vj are connected with at least a and at most b (directed or undirected) edges. If G(a, b, n) is directed, then it is called (a, b, n)-digraph and if it is undirected, then it is called (a, b, n)undigraph. Landau in 1953 published an algor...
متن کاملDiamond-free Degree Sequences
While attempting to classify partial linear spaces produced during the execution of an extension of Stinson’s hill-climbing algorithm a new problem arises, that of generating all graphical degree sequences that are diamond-free (i.e. have no diamond as subgraph) and satisfy additional constraints. We formalize this new problem, propose a constraint programming solution and list all satisfying d...
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: Linear Algebra and its Applications
سال: 1989
ISSN: 0024-3795
DOI: 10.1016/0024-3795(89)90470-9