Jack H. Koolen

most citedShilla distance-regular graphs

3 citations · 3 across the 3 of their papers we have counts for

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math.CO2009

Bounds for the Huckel energy of a graph

Ebrahim Ghorbani, Jack H. Koolen, Jae Young Yang

Let $G$ be a graph on $n$ vertices with $r := ⌊ n /2 ⌋$ and let $λ_{1} \geq ... \geq λ_{n}$ be adjacency eigenvalues of $G$ . Then the Hückel energy of $G$ , HE( $G$ ), is defi…

math.CO2009

On Distance-Regular Graphs with Smallest Eigenvalue at Least $- m$

J. H. Koolen, S. Bang

A non-complete geometric distance-regular graph is the point graph of a partial geometry in which the set of lines is a set of Delsarte cliques. In this paper, we prove that for fi…

math.CO2009★ 3 cited

Shilla distance-regular graphs

Jack H. Koolen, Jongyook Park

A Shilla distance-regular graph G (say with valency k) is a distance-regular graph with diameter 3 such that its second largest eigenvalue equals to a3. We will show that a3 divide…

Bounds for the Huckel energy of a graph

On Distance-Regular Graphs with Smallest Eigenvalue at Least −m

Shilla distance-regular graphs

On Distance-Regular Graphs with Smallest Eigenvalue at Least $- m$