Hypergraphs with infinitely many extremal constructions

报告题目:Hypergraphs with infinitely many extremal constructions

报告人:侯建锋,福州大学教授

报告时间:20229249:00-10:00 

报告地点:讯会议499-232-684

报告摘要: 

We give the first exact and stability results for a hypergraph Tur\'{a}n problem with infinitely many  extremal constructions that are far from each other in edit-distance. This includes an example of triple systems with Tur\'{a}n density $2/9$, thus answering some questions posed by the third and fourth authors and Reiher about the feasible region of hypergraphs. Our novel approach is to construct certain multilinear polynomials that attain their maximum (in the standard simplex) on a line segment and then use these polynomials to define an operation on hypergraphs that gives extremal constructions (Join work with Heng Li, Xizhi Liu, Dhruv Mubayi and Yixiao Zhang).

报告人简介:

侯建锋,福州大学教授,博士生导师。20097月毕业于山东大学手机网投大平台,获理学博士学位。2011年度全国优秀博士学位论文提名奖,2011年度福建省自然科学基金杰出青年项目获得者,2020年入选福建省“雏鹰计划”青年拔尖人次,主持国家自然科学基金4项,参与重点项目一项。目前为中国数学会组合数学与图论专业委员会委员,中国工业与应用数学学会图论组合及应用专业委员会委员,福建省数学会常务理事,Frontiers of Computer Science青年AE。主要从事图论及其应用研究,解决了包括英国皇家学会会员Bollobas等人提出的图划分领域的多个猜想和公开问题,发表学术论文60余篇。


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