报告题目：Why are there six degrees of separation in a social network?

报告人：Stefano Boccaletti 教授

主持人：管曙光 教授

报告时间：6月16日上午10:00

报告地点：闵行校区物理楼226报告厅

报告人简介：

Stefano Boccaletti教授，欧洲科学院院士，意大利国家科学院复杂系统研究所常务研究主任，以色列特拉维夫大学名誉教授，以色列魏兹曼科学研究院访问科学家主要从事复杂网络、系统同步、非线性动力学、大数据光电物理学、认知神经科学、混沌控制相关的基础和交叉学科领域研究，在《Physics Reports》《Physical Review Letters》《Physical Review E》 《Science Advances》《PNAS》《Nature Physics》《Nature Communications》《Nature Scientific Reports》等国际SCI杂志发表论文402篇，总引用数超过34000次，H指数62i-10指数221，2006年发表在《Physics Reports》上的论文《Complex Networks: Structure and Dynamics》被引用超过12000次，并为该期刊年鉴上被引用次数最多的论文。

报告摘要：

The story coined the expression ‘six degrees of separation’ to reflect the idea that all people of the world are six or fewer social connections apart from each other. A clear explanation of the mechanisms through which social networks organize into ultra-small world states (where the diameter does not depend on the system size over several orders of magnitude) is, however, still missing. In my talk, I will show that the mechanism behind such observed regularity can be found in a dynamic evolution of the network. Therefore, evolutionary rules of the kind traditionally associated with human cooperation and altruism can in fact account also for the emergence of such a famous attribute of social networks.