Discontinuous and continuous transitions of collective behaviors in living systems  

作　　者：Xu Li Tingting Xue Yu Sun Jingfang Fan Hui Li Maoxin Liu Zhangang Han Zengru Di Xiaosong Chen 李旭;薛婷婷;孙宇;樊京芳;李辉;刘卯鑫;韩战钢;狄增如;陈晓松(School of Systems Science,Beijing Normal University,Beijing 100878,China;Institute of Nonequilibrium Systems,Beijing Normal University,Beijing 100878,China;School of Science,Beijing University of Posts and Telecommunications,Beijing 100876,China)

机构地区：[1]School of Systems Science,Beijing Normal University,Beijing 100878,China [2]Institute of Nonequilibrium Systems,Beijing Normal University,Beijing 100878,China [3]School of Science,Beijing University of Posts and Telecommunications,Beijing 100876,China

出　　处：《Chinese Physics B》2021年第12期160-166,共7页中国物理B（英文版）

基　　金：Project supported by the Fundamental Research Funds for the Central Universities,China(Grant No.2019XD-A10);the National Natural Science Foundation of China(Grant No.71731002)。

摘　　要：Living systems are full of astonishing diversity and complexity of life.Despite differences in the length scales and cognitive abilities of these systems,collective motion of large groups of individuals can emerge.It is of great importance to seek for the fundamental principles of collective motion,such as phase transitions and their natures.Via an eigen microstate approach,we have found a discontinuous transition of density and a continuous transition of velocity in the Vicsek models of collective motion,which are identified by the finite-size scaling form of order-parameter.At strong noise,living systems behave like gas.With the decrease of noise,the interactions between the particles of a living system become stronger and make them come closer.The living system experiences then a discontinuous gas-liquid like transition of density.The even stronger interactions at smaller noise make the velocity directions of the particles become ordered and there is a continuous phase transition of collective motion in addition.

关 键 词：living systems phase emergence phase transitions eigen mircostate 

分 类 号：N941.1[自然科学总论—系统科学]