J. Koolen

activity

20012026

most citedDistance-regular graphs

186 citations · 238 across the 42 of their papers we have counts for

collaborators

Showing 2015Show all

4 papers · 1 filter

math.CO2015

Hypercubes are determined by their distance spectra

Jack. H. Koolen, Sakander Hayat, Quaid Iqbal

We show that the d-cube is determined by the spectrum of its distance matrix.

math.CO2015

Light tails and the Hermitian dual polar graphs

Jack Koolen, Zhi Qiao

Juriśič et al. conjectured that if a distance-regular graph $Γ$ with diameter $D$ at least three has a light tail, then one of the following holds: 1. $a_{1} = 0$ ; 2. $Γ$ is an antipoda…

math.CO2015★ 2 cited

A characterization of the graphs of bilinear $(d \times d)$ -forms over $F_{2}$

Alexander L. Gavrilyuk, Jack H. Koolen

The bilinear forms graph denoted here by $B i l_{q} (e \times d)$ is a graph defined on the set of $(e \times d)$ -matrices ( $e \geq d$ ) over $F_{q}$ with two matrices being adjacent…

math.CO2015★ 3 cited

Distance-regular graphs with valency k having smallest eigenvalue at most -k/2

Jack Koolen, Zhi Qiao

In this paper, we study the non-bipartite distance-regular graphs with valency k and having a smallest eigenvalue at most -k/2.

Hypercubes are determined by their distance spectra

Light tails and the Hermitian dual polar graphs

A characterization of the graphs of bilinear (d×d)-forms over F2​

Distance-regular graphs with valency k having smallest eigenvalue at most -k/2

A characterization of the graphs of bilinear $(d \times d)$ -forms over $F_{2}$