91直播

91直播：张军阳(重庆师范大学)

时间：2024年06月17日 09：30-

地址：理科楼LA103

摘要：For positive integers k and n, the shuffle group G_k,kn is generated by the k! permutations of a deck of kn cards performed by cutting the deck into k piles with n cards in each pile, and then perfectly interleaving these cards following certain order of the k piles. For k=2, the shuffle group G_2,2n has been determined by Diaconis, Graham and Kantor in 1983. The Shuffle Group Conjecture states that, for general k, the shuffle group G_k,kn contains A_kn whenever k is not 2 or 4 and n is not a power of k. In particular, the conjecture in the case k=3 was posed by Medvedoff and Morrison in 1987. The only values of k for which the Shuffle Group Conjecture has been confirmed so far are powers of 2, due to recent work of Amarra, Morgan and Praeger based on Classification of Finite Simple Groups. In this talk, I introduce our recent work on confirming the Shuffle Group Conjecture for all cases using results on 2-transitive groups with elements of large fixed point ratio. This is a joint work with Binzhou Xia, Zhishuo Zhang and Wenying Zhu.

简介：张军阳，重庆师范⼤学副教授，主要研究领域为有限群论与组合数学。2012年毕业于⾸都师范⼤学数学科学91直播 ，获理学博⼠学位。⾄今已在 J. Combin. Theory Ser. A，European J. Combin.， J. Group Theory，Designs, Codes and Cryptography等国际SCI期刊上公开发表论文20余篇。已完成国家⾃然科学基⾦青年基⾦项⽬1项，参与国家⾃然科学基⾦⾯上项⽬2项。

邀请人：傅士硕

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