English

On the minimal sum of edges in a signed edge-dominated graph

Combinatorics 2021-05-11 v2

Abstract

Let GG be a simple graph with nn vertices and ±1\pm 1-weights on edges. Suppose that for every edge ee the sum of edges adjacent to ee (including ee itself) is positive. Then the sum of weights over edges of GG is at least n225-\frac{n^2}{25}. Also we provide an example of a weighted graph with described properties and the sum of weights (1+o(1))n28(1+2)2-(1+o(1))\frac{n^2}{8(1 + \sqrt{2})^2}. The previous best known bounds were n216-\frac{n^2}{16} and (1+o(1))n254-(1+o(1))\frac{n^2}{54} respectively. We show that the constant 1/54-1/54 is optimal under some additional conditions.

Keywords

Cite

@article{arxiv.2012.09956,
  title  = {On the minimal sum of edges in a signed edge-dominated graph},
  author = {Danila Cherkashin and Pavel Prozorov},
  journal= {arXiv preprint arXiv:2012.09956},
  year   = {2021}
}

Comments

12 pages, 7 figures