Polynomials Counting Nowhere-Zero Chains in Graphs

Author:

Kochol Martin

Abstract

We introduce polynomials counting nowhere-zero chains in graphs – nonhomogeneous analogues of nowhere-zero flows. For a graph $G$, an Abelian group $A$, and $b:V(G)\to A$, let $\alpha_{G,b}$ be a mapping from $\Lambda(G)$ (a family of vertex sets of connected subgraphs of $G$ satisfying an additional condition) to $\{0,1\}$ such that for each $X\in\Lambda(G)$, $\alpha_{G,b}(X)=0$ if and only if $\sum_{v\in X}b(v)=0$. We prove that there exists a polynomial function $F(G,\alpha;k)$ ($\alpha=\alpha_{G,b}$) of $k$ such that for any Abelian group $A'$ of order $k$ and each $b':V(G)\to A'$ satisfying $\alpha_{G,b'}=\alpha$, $F(G,\alpha;k)$ equals the number of nowhere-zero $A'$-chains $\varphi$ in $G$ having boundaries equal to $b'$. In particular $F(G,\alpha;k)$ is the flow polynomial of $G$ if $\alpha(X)=0$ for each $X\in\Lambda(G)$. Finally we characterize $\alpha$ for which $F(G,\alpha;k)$ is nonzero and show that in this case $F(G,\alpha;k)$ has the same degree as the flow polynomial of $G$.

Publisher

The Electronic Journal of Combinatorics

Subject

Computational Theory and Mathematics,Geometry and Topology,Theoretical Computer Science,Applied Mathematics,Discrete Mathematics and Combinatorics

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3