Encyclopedia of Social Network Analysis and Mining

Living Edition
| Editors: Reda Alhajj, Jon Rokne

Networks in the Twenty-First Century

  • Sune Lehmann
Living reference work entry
DOI: https://doi.org/10.1007/978-1-4614-7163-9_80-1




The degree ki of a network node i is its number of neighbors.


A power is an exponent to which a given quantity is raised, for example, x to the ath power, xa.

Power Law

When the probability of an event is proportional to a power of some attribute of that event (e.g., its size), the probability distribution is said to be described by a power law.


Division of a set into non-overlapping subsets.


Networks have a long history in a number of fields ranging from sociology to mathematics. This article describes surge of interest in networks in the early twenty-first century (sometimes called network science), in large part driven by interest from the statistical physics community.


The study of networks has a deep history in mathematics, sociology, biology, and computer science reaching back to the 1700. But the twenty-first century is when the study of networks grew into a science in its...


Degree Distribution Cluster Coefficient Random Network Community Detection Preferential Attachment 
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The author would like to thank Vedran Sekara for insightful comments on the manuscript.


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© Springer Science+Business Media LLC 2016

Authors and Affiliations

  1. 1.DTU Compute, Technical University of DenmarkKgs. LyngbyDenmark