报告题目：Why Are There Six Degrees of Separation in a Social Network?

报告所属学科：管理科学与工程

报告人：Stefano Boccaletti（意大利国家科学院复杂系统研究所）

报告时间：2024年6月8日 14:00-15:00

报告地点：经管学院207室

报告摘要：

A wealth of evidence shows that real-world networks are endowed with the small-world property, i.e., that the maximal distance between any two of their nodes scales logarithmically rather than linearly with their size. In addition, most social networks are organized so that no individual is more than six connections apart from any other, an empirical regularity known as the six degrees of separation. Why social networks have this ultrasmall-world organization, whereby the graph’s diameter is independent of the network size over several orders of magnitude, is still unknown. I will show that the “six degrees of separation” is the property featured by the equilibrium state of any network where individuals weigh between their aspiration to improve their centrality and the costs incurred in forming and maintaining connections. I will show, moreover, that the emergence of such a regularity is compatible with all other features, such as clustering and scale-freeness, that normally characterize the structure of social networks. Thus, simple evolutionary rules of the kind traditionally associated with human cooperation and altruism can also account for the emergence of one of the most intriguing attributes of social networks.

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、终身高级研究员，入选欧盟“玛丽·居里”学者人才计划，以色列特拉维夫大学名誉教授。Stefano Boccaleti于1995年在佛罗伦萨大学获得物理学博士学位，并于2015年在马德里胡安·卡洛斯国王大学获得荣誉博士学位。他在2007-2011年和2014-2018年期间担任意大利驻以色列大使馆的科学专员。他的主要科学兴趣是（1）传播媒体中的模式形成和竞争，（2）混沌的控制和同步，以及（3）复杂网络的结构和动力学。他从2013年起担任Chaos Solitons & Fractals（IF=7.8）杂志的主编。Boccalett教授在同行评审的国际期刊上发表了402篇论文，被引用超过36200次（谷歌学术）。他的h因子是71，他的i-10指数是232。Boccalett教授已累计在Nature Physics, PNAS, Physical Review Letters, Science Advances等学术期刊发表论文200多篇，论文引用35000余次，单篇论文最高引用近12000次。研究成果多次被Nature News, LiveScience, ScienceDaily, Phys.Org, Complexity Digest等科学媒体报道和转载。