On realization graphs of degree sequences
نویسنده
چکیده
Given the degree sequence d of a graph, the realization graph of d is the graph having as its vertices the labeled realizations of d, with two vertices adjacent if one realization may be obtained from the other via an edge-switching operation. We describe a connection between Cartesian products in realization graphs and the canonical decomposition of degree sequences described by R.I. Tyshkevich and others. As applications, we characterize the degree sequences whose realization graphs are triangle-free graphs or hypercubes.
منابع مشابه
The Tree of Trees: on methods for finding all non-isomorphic tree-realizations of degree sequences
A degree sequence for a graph is a list of positive integers, one for every vertex, where each integer corresponds to the number of neighbors of that vertex. It is possible to create sequences that have no corresponding graphs, as well as sequences that correspond to multiple distinct (i.e., non-isomorphic) graphs. A graph that corresponds to a given degree sequence is called a realization of t...
متن کاملOn Fractional Realizations of Graph Degree Sequences
We introduce fractional realizations of a graph degree sequence and a closely associated convex polytope. Simple graph realizations correspond to a subset of the vertices of this polytope; we characterize degree sequences for which each polytope vertex corresponds to a simple graph realization. These include the degree sequences of threshold and pseudo-split graphs, and we characterize their re...
متن کاملThe Connection between the Number of Realizations for Degree Sequences and Majorization
The graph realization problem is to find for given nonnegative integers a1, . . . , an a simple graph (no loops or multiple edges) such that each vertex vi has degree ai. Given pairs of nonnegative integers (a1, b1), . . . , (an, bn), (i) the bipartite realization problem ask whether there is a bipartite graph (no loops or multiple edges) such that vectors (a1, ..., an) and (b1, ..., bn) corres...
متن کاملRealizing Degree Sequences with Graphs Having Nowhere-Zero 3-Flows
The following open problem was proposed by Archdeacon: Characterize all graphical sequences π such that some realization of π admits a nowhere-zero 3-flow. This open problem is solved in this paper with the following complete characterization: A graphical sequence π = (d1, d2, . . . , dn) with minimum degree at least two has a realization that admits a nowhere-zero 3-flow if and only if π 6= (3...
متن کاملOn reverse degree distance of unicyclic graphs
The reverse degree distance of a connected graph $G$ is defined in discrete mathematical chemistry as [ r (G)=2(n-1)md-sum_{uin V(G)}d_G(u)D_G(u), ] where $n$, $m$ and $d$ are the number of vertices, the number of edges and the diameter of $G$, respectively, $d_G(u)$ is the degree of vertex $u$, $D_G(u)$ is the sum of distance between vertex $u$ and all other vertices of $G$, and $V(G)$ is the...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Discrete Mathematics
دوره 339 شماره
صفحات -
تاریخ انتشار 2016