popular nodes are informed, a symmetric argument can show that after
another O(log(n)3/4 log(log(n))) rounds,
the remaining small-degree nodes,
mostly by calling more popular nodes,
would all be informed; for more, see
Doerr et al.
We simulated a natural rumor-spreading process on various graphs representing real-world social networks
and several classical network topologies. We also performed a mathematical analysis of the process in PA
graphs. Simulation and analysis both
demonstrate the speediness of rumor
spreading in social networks.
A key observation in the mathematical proof, as well as being a good
explanation for this phenomenon, is
that small-degree nodes learn a rumor
once one of their neighbors knows it,
then quickly forward it to their neighbors. This propagation scheme facilitates sending rumors from one large-degree node to another.
How does this play out in everyday
life? It partially explains why social
networks are observed to spread information quickly, even though the
process is not organized centrally,
and the network is not designed in
an intelligent way. Crucial is fruitful
interaction between hubs with many
connections and average users with
few friends. Hubs make the news
available to a big audience, whereas
average users quickly convey the information from one neighbor to the
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Benjamin Doerr ( firstname.lastname@example.org) is a senior
researcher in the department of algorithms and
Complexity at Max-Planck-Institut für Informatik,
saarbrücken, Germany, and an adjunct professor at
saarland university, saarbrücken, Germany.
Mahmoud Fouz ( email@example.com)
is a managing director of rocket Internet, dubai, u.a.e.;
this work was done while he was a Ph.d. student in the
Computational Complexity group of the department of
Computer science at saarland university, saarbrücken,
Tobias Friedrich ( firstname.lastname@example.org) is an
independent research group leader in the Cluster of
excellence on Multimodal Computing and Interaction
at saarland university, saarbrücken, Germany, and
a senior researcher in the department of algorithms
and Complexity at Max-Planck-Institut für Informatik,
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