報告題目： From Friendship Graph to Mixed Extension
報 告 人：王建鋒教授 山東理工大學
報告時間：2021年5月31日 14:00-15:00
報告地點：數學樓三樓天元數學東北中心第五研讨室
校内聯系人：孫曉松 sunxs@jlu.edu.cn
報告摘要： In 2010, it was conjectured that the friendship graphs are determined by the adjacency spectra. In 2013, Das claimed that he proved the conjecture. However, his proof was found to be incorrect since the interlace theorem was misused. Determining the graphs with all but two eigenvalues equal to ±1, Cioaba et al. completely solved this conjecture in 2015. Inspired by the methods used in their paper, Cioaba et al. further investigated the related problems, and Haemers posed a new method named as the mixed extension of graphs. In this report, the old and new results involving the above topics will be summarized and introduced.
報告人簡介：王建鋒，山東理工大學數學與統計學院教授，博士生導師，擔任中華全國青年聯合會第十二屆委員會委員、中國科學技術協會第九次全國代表大會代表委員、中國青年科技工作者協會第五屆理事會理事、中國運籌學會圖論與組合分會第四屆理事會青年理事、青海數學學會第十屆理事會秘書長等。主要研究領域是圖論及其應用，側重于代數圖論方面的研究，主要包括圖的譜理論及其應用和圖的多項式理論及其應用等。擔任美國“數學評論”評論員和十餘種SCI源期刊和核心期刊審稿人。曾獲青海省“昆侖英才”計劃科技創新領軍人才，青海省自然科學與工程學科帶頭人，第17屆青海青年五四獎章。
