Neighborhood Complexes of Kneser Graphs, $K{G}_{3,k}$

Abstract

In this article, we prove that the neighborhood complex of the Kneser graph $K{G}_{3,k}$ is of the same homotopy type as that of a wedge of $\frac{(k+1)(k+3)(k+4)(k+6)}{4}+1$ spheres of dimension $k$. We construct a maximal subgraph $S_{3,k}$ of $K{G}_{3,k}$, whose neighborhood complex deformation retracts onto the neighborhood complex of $S{G}_{3,k}$.

arXiv comment20 pages. arXiv admin note: text overlap with arXiv:1802.05848