Title
An entropy based proof of the Moore bound for irregular graphs
Abstract
We provide proofs of the following theorems by considering the entropy of random walks: Theorem 1.(Alon, Hoory and Linial) Let G be an undirected simple graph with n vertices, girth g, minimum degree at least 2 and average degree d: Odd girth: If g=2r+1,then n \geq 1 + d*(\Sum_{i=0}^{r-1}(d-1)^i) Even girth: If g=2r,then n \geq 2*(\Sum_{i=0}^{r-1} (d-1)^i) Theorem 2.(Hoory) Let G = (V_L,V_R,E) be a bipartite graph of girth g = 2r, with n_L = |V_L| and n_R = |V_R|, minimum degree at least 2 and the left and right average degrees d_L and d_R. Then, n_L \geq \Sum_{i=0}^{r-1}(d_R-1)^{i/2}(d_L-1)^{i/2} n_R \geq \Sum_{i=0}^{r-1}(d_L-1)^{i/2}(d_R-1)^{i/2}
Year
Venue
Keywords
2010
Clinical Orthopaedics and Related Research
bipartite graph,random walk,discrete mathematics
Field
DocType
Volume
Graph,Discrete mathematics,Combinatorics,Moore graph,Graph power,Vertex (geometry),Random walk,Biregular graph,Bipartite graph,Moore bound,Mathematics
Journal
abs/1011.1
Citations 
PageRank 
References 
1
0.38
2
Authors
2
Name
Order
Citations
PageRank
Ajesh Babu171.20
Jaikumar Radhakrishnan2112396.04