时间：2017年12月20日（星期三）15：30—16：30
地点:旗山校区理工楼北601报告厅
主讲人：Takashi Kumagai, the Research Institute for Mathematical Sciences (RIMS), Kyoto University
专家简介: Takashi Kumagai is a professor at the Research Institute for Mathematical Sciences (RIMS), Kyoto University. His research areas are anomalous diffusions on disordered media, and potential theory for jump processes on metric measure spaces. He gave the traditional St. Flour 2010 lectures in France, was a plenary speaker at SPA 2010 in Osaka, an invited speaker at the International Congress of Mathematicians in Seoul 2014, and a Medallion lecturer of IMS in 2017. Prestigious prizes he got include the following: Spring prize of the Mathematical Society of Japan (2004), JSPS (Japan Society for the Promotion of Science) Prize (2012), Inoue Prize for Science (2017). He served as editors of many major journals in probability and beyond, including the chief editor of Stochastic Processes and Their Applications (2012-2015), Journal of Math. Soc. Japan (2016-).
报告摘要：In this talk, we show that the total-variation mixing time of the lamplighter random walk on fractal graphs exhibit sharp cutoff when the underlying graph is transient (namely of spectral dimension greater than two). In contrast, we show that such cutoff can not occur for strongly recurrent underlying graphs (i.e. of spectral dimension less than two).This is a joint work with A. Dembo (Stanford) and C. Nakamura (Kyoto).