报告人：严慧芳

时 间：2026年10月24日 15:30

地 点：L-2620

报告摘要：A partially ordered pattern (abbreviated POP) is a partially ordered set (poset) that generalizes the notion of a pattern when we are not concerned with the relative order of some of its letters. We study a family of broom-shaped POPs consisting of a chain of length k and m pairwise incomparable elements above the chain. For 0≤s≤m, label the chain increasingly from bottom to top by s+1, s+2, … , s+k, and assign the remaining labels to the incomparable elements. We prove that, for fixed k and m, these POPs are Wilf-equivalent for all 0≤s≤m. This is accomplished by establishing a bijection via 01-fillings of polyominoes.

专家简介：严慧芳，浙江师范大学数学科学学院教授，博士生导师，2006 年毕业于南开大学组合数学中心，获理学博士学位。主要从事组合数学研究，研究工作涉及排列统计量、模式避免及组合结构的双射计数等。研究成果发表于 J. Combin. Theory Ser. A,Advances in Applied Mathematics, European J. Combin., Journalof Algebraic Combinatorics 等期刊。先后主持国家自然科学基金面上项目3项, 青年基金项目1项及浙江省自然科学基金一般项目 1 项。