AN ERDOS-KO-RADO THEOREM FOR THE DERANGEMENT GRAPH OF PGL(3)(q) ACTING ON THE PROJECTIVE PLANE

作者：Meagher Karen^*; Spiga Pablo

来源：SIAM Journal on Discrete Mathematics, 2014, 28(2): 918-941.

DOI：10.1137/13094075X

• derangement graph
• independent sets
• Erdos-Ko-Rado theorem

In this paper we prove an Erdos-Ko-Rado-type theorem for intersecting sets of permutations. We show that an intersecting set of maximal size in the projective general linear group PGL(3)(q), in its natural action on the points of the projective line, is either a coset of the stabilizer of a point or a coset of the stabilizer of a line. This gives the first evidence for the veracity of Conjecture 2 from K. Meagher and P. Spiga, An Erdos-Ko-Rado Theorem for the Derangement Graph of PGL(2, q) Acting on the Projective Line [J. Combin. Theory Ser. A, 118 (2011), pp. 532-544].

• 出版日期2014