报告一：Saturation Numbers for Disjoint Stars
时间：5月1日下午2点
摘要:
A graph $G$ is called an $H$-saturated if $G$ does not contain $H$ as a subgraph, but the addition of any edge between two nonadjacent vertices in $G$ results in a copy of $H$ in $G$. The saturation number $sat(n,H)$ is the minimum number of edges in $G$ for all $H$-saturated graphs $G$ of order $n$. For a graph $F$, let $mF$ denote the disjoint union of $m$ copies of $F$. In 2011, Faudree, Faudree and Schmitt proposed a problem that is to determine $sat(n,mK_{1,k})$ for all $m$ and $k$. In this talk, I will give a result on $ sat(n,mK_{1,k})$ when $m\ge 2$, $k\ge 4$ and $n\ge 3mk^2$. This work is joint with Zequn Lv and Zhen He.
个人简介：陆 玫，1993年7月在中国科学院数学与系统科学研究院获博士学位，现为清华大学数学科学系教授，博士生导师，主要从事运筹学、图论与组合优化方面的研究。
报告二：Turán number for odd-ballooning of trees
时间：5月2日上午9点
摘要:
The Turán number ex(n,H) is the maximum number of edges in an H-free graph on n vertices. Let T be any tree. The odd-ballooning of T, denoted by To, is a graph obtained by replacing each edge of T with an odd cycle containing the edge, and all new vertices of the odd cycles are distinct. In this paper, we determine the exact value of ex(n, To) for sufficiently large n and To being good, which generalizes all the known results on ex(n, To) for T being a star, due to Erdős et al. (1995), Hou et al. (2018) and Yuan (2018), and provides some counterexamples with chromatic number 3 to a conjecture of Keevash and Sudakov (2004), on the maximum number of edges not in any monochromatic copy of H in a 2-edge-coloring of a complete graph of order n.
个人简介：陈耀俊，南京大学数学系教授，博士生导师。2000年7月在中国科学院数学与系统科学研究院获理学博士学位；2000.7-2002.6在南京大学数学系从事博士后研究工作；2003.9-2005.8在香港理工大学商学院物流系从事博士后研究工作；目前主要从事图中特定子图结构、Ramsey 数以及编码理论、理论计算机与组合图论交叉问题的研究。先后主持国家自然科学基金多项，在国内外专业学术杂志上发表研究论文80余篇。
报告三：The extremal average distance of cubic graphs
时间：5月2日下午2点
摘要：
The average distance µ(G) of a simple connected graph G is the average of the distances between all pairs of vertices in G. We prove that for a connected cubic graph G on n vertices, µ(G) ≤ n 3−16n+48 4(n2−n) , if n = 4k + 2; and µ(G) ≤ n 3−32n+128 4(n2−n) , if n = 4k + 4. Furthermore, all extremal graphs attaining the upper bounds are characterized, and they have the maximum possible diameter. The result solves a question of Plesn´ık and proves a conjecture of Knor, Skrekovski and Tepeh on the average distance of cubic graphs. The ˇ proofs use graph transformations and structural graph analysis. This talk is joined with Yi-Ze Chen, Xin Li (Shanghai Jiao Tong University).
个人简介： 张晓东，上海交通大学数学科学学院教授、博士生导师。1998年6月在中国科学技术大学获得理学博士学位。曾在以色列理工学院(得到Lady Davis Postdoctoral fellowship 资助)和智利大学做博士后、在美国加州大学圣地亚哥分校等校做访问学者。多次主持和参加国家自然科学基金等项目。已经在国内外SCI期刊发表160多篇论文，出版专著一本。担任中国运筹学会图论组合分会副理事长和2个国际杂志编委。目前主要研究领域为谱图理论，随机图与复杂网络，组合矩阵论等。
报告四：Inertia indices and eigenvalue inequalities for Hermitian matrices
时间：5月3日上午9点
摘要：
We present a characterization of eigenvalue inequalities between two Hermitian matrices by means of inertia indices. As applications, we deal with some classical eigenvalue inequalities for Hermitian matrices, including the Cauchy interlacing theorem and the Weyl inequality, in a simple and unified approach. We also give a common generalization of eigenvalue inequalities for (Hermitian) normalized Laplacian matrices of simple (signed, weighted, directed) graphs.
个人简介：王毅，大连理工大学数学科学学院二级教授、博士生导师。研究方向为组合数学，主要研究兴趣包括计数组合学、解析组合学、极值组合学和图论。在组合不等式的研究中做出了一些有影响的工作，多项研究成果以定理形式出现在国外多部专著中。主持过多项国家和省部级基金项目。现任大连理工大学数学一级学科博士点点长、中国运筹学会图论组合分会副理事长、中国工业与应用数学学会图论组合及应用专业委员会副主任、中国数学会组合数学与图论专业委员会常务委员、中国数学会《应用数学学报》（英文版）编委。
报告五：List star edge coloring of sparse graphs
时间：5月3日下午2点
摘要：
A star-edge coloring of a graph G is a proper edge coloring such that every 2-colored connected subgraph of G is a path of length at most 3. For a graph G, let the list star chromatic index of G, ch'(s)(G), be the minimum k such that for any k-uniform list assignment L for the set of edges, G has a star-edge coloring from L. Dvorak et al. (2013) asked whether the list star chromatic index of every subcubic graph is at most 7. We present some new results.
个人简介：南京大学博士，中国科学技术大学博士后，现任江苏师范大学教授、副校长、安徽大学兼职博士生导师。入选江苏省“333高层次人才培养工程”中青年科学技术带头人、江苏省高校“青蓝工程”中青年学术带头人。担任中国运筹学会常务理事及其组合图论分会副理事长、中国工业与应用数学学会图论组合及应用专业委员会常务委员、中国数学会组合数学与图论专业委员会常务委员、江苏省工业与应用数学学会副理事长、江苏省数学会监事和《数学教育学报》副董事长。主要研究兴趣为组合矩阵论和图的染色理论。先后主持国家自然科学基金面上项目4项、参加国家自然科学基金重点项目1项，发表学术论文100余篇、教学研究论文4篇，获教育部优秀科研成果自然科学二等奖1项，获江苏省优秀教学成果奖二等奖2项、江苏省第三届教育科学优秀成果实际创新类二等奖1项。