MathDB
Graph with inequality

Source: Tuymadaa Senior 2024 P8

July 7, 2024
inequalitiesgraph theorygraph

Problem Statement

A graph GG has nn vertices (n>1n>1). For each edge ee let c(e)c(e) be the number of vertices of the largest complete subgraph containing ee. Prove that the inequality (the summation is over all edges of GG): ec(e)c(e)1n22.\sum_{e} \frac{c(e)}{c(e)-1}\le \frac{n^2}{2}.