Network Science is not scale invariant
Visiting speaker
Santo Fortunato
Visiting Professor, Indiana University
Past Talk
Hybrid talk
Friday
Oct 27, 2023
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4:00 pm
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In many complex networks, the unit adopted to measure the edge weightsis arbitrary and immaterial. Therefore, we argue that rescaling theweight of all edges of any network by a constant factor should notaffect any conclusion or deduction we can make on the system. Whileall network science metrics are indeed invariant with respect to thischange of scale, we show that the assessment of the statistical significanceof the values of these score is instead scale-dependent, with respect tocurrent null models. The reason lies in the peculiar probabilitydistribution the null models are based on. This result calls for amodification of current null models, or at least a redefinition oftheir extension to weighted networks.

About the speaker
About the speaker
Santo Fortunato is a Professor at Luddy School of Informatics, Computing, and Engineering of Indiana University. Previously he was professor of complex systems at the Department of Computer Science of Aalto University, Finland. Prof. Fortunato got his PhD in Theoretical Particle Physics at the University of Bielefeld In Germany. His focus areas are network science, especially community detection in graphs, computational social science and science of science. His research has been published in leading journals, including Nature, Science, Nature Physics, PNAS, Physical Review Letters, Physical Review X, Reviews of Modern Physics, Physics Reports and has collected over 44,000 citations (Google Scholar). His single-author article Community detection in graphs (Physics Reports 486, 75-174, 2010) is one of the best known and most cited papers in network science. Fortunato received the Young Scientist Award for Socio- and Econophysics 2011, a prize given by the German Physical Society, for his outstanding contributions to the physics of social systems. He is Fellow of the Network Science Society (2022) and of the American Physical Society (2022). He is the Founding Chair of the International Conference of Computational Social Science (IC2S2), which he first organized in Helsinki in June 2015. He was Chair of Networks 2021, the largest ever event on network science, a historical merger of the NetSci and Sunbelt conferences. He is author of the book A First Course in Network Science, by Cambridge University Press (2020), the most accessible textbook on the new science of networks.
Santo Fortunato is a Professor at Luddy School of Informatics, Computing, and Engineering of Indiana University. Previously he was professor of complex systems at the Department of Computer Science of Aalto University, Finland. Prof. Fortunato got his PhD in Theoretical Particle Physics at the University of Bielefeld In Germany. His focus areas are network science, especially community detection in graphs, computational social science and science of science. His research has been published in leading journals, including Nature, Science, Nature Physics, PNAS, Physical Review Letters, Physical Review X, Reviews of Modern Physics, Physics Reports and has collected over 44,000 citations (Google Scholar). His single-author article Community detection in graphs (Physics Reports 486, 75-174, 2010) is one of the best known and most cited papers in network science. Fortunato received the Young Scientist Award for Socio- and Econophysics 2011, a prize given by the German Physical Society, for his outstanding contributions to the physics of social systems. He is Fellow of the Network Science Society (2022) and of the American Physical Society (2022). He is the Founding Chair of the International Conference of Computational Social Science (IC2S2), which he first organized in Helsinki in June 2015. He was Chair of Networks 2021, the largest ever event on network science, a historical merger of the NetSci and Sunbelt conferences. He is author of the book A First Course in Network Science, by Cambridge University Press (2020), the most accessible textbook on the new science of networks.