A spectral characterization of the s-clique extension of the square grid graphs. (February 2019)

• Record Type: Journal Article
• Authors: Hayat, Sakander; Koolen, Jack H.; Riaz, Muhammad
• Is Part Of: European journal of combinatorics. Volume 76(2019)
• Page Start: 104
• Page End: 116
• Publication Date: 2019-02
• Subjects: Combinatorial analysis -- Periodicals; Analyse combinatoire -- Périodiques; Combinatorial analysis; Periodicals; Electronic journals; 511.6
• DOI: 10.1016/j.ejc.2018.09.009
• Languages: English
• ISSNs: 0195-6698

Abstract

Abstract: In this paper we show that for integers s ≥ 2, t ≥ 1, any co-edge-regular graph which is cospectral with the s -clique extension of the t × t -grid is the s -clique extension of the t × t -grid, if t is large enough. Gavrilyuk and Koolen used a weaker version of this result to show that the Grassmann graph J q ( 2 D, D ) is characterized by its intersection array as a distance-regular graph, if D is large enough.