Evangelism in Social Networks

  • Gennaro Cordasco
  • Luisa Gargano
  • Adele A. Rescigno
  • Ugo Vaccaro
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9843)


We consider a population of interconnected individuals that, with respect to a piece information, at each time instant can be subdivided into three (time-dependent) categories: agnostic, influenced, and evangelists. A dynamical process of information diffusion evolves among the individuals of the population according to the following rules. Initially, all individuals are agnostic. Then, a set of people is chosen from the outside and convinced to start evangelizing, i.e., to start spreading the information. When a number of evangelists, greater than a given threshold, communicate with an node v, the node v becomes influenced, whereas, as soon as the individual v is contacted by a sufficiently much larger number of evangelists, it is itself converted into an evangelist and consequently it starts spreading the information. The question is: How to choose a bounded cardinality initial set of evangelists so as to maximize the final number of influenced individuals? We prove that the problem is hard to solve, even in an approximate sense, and we present exact polynomial time algorithms for trees and complete graphs. For general graphs, we derive exact algorithms parameterized with respect to neighborhood diversity. We also study the problem when the objective is to select a minimum number of evangelists able of influencing the whole network.


Vertex Cover Neighborhood Diversity Tree Decomposition Fixed Parameter Tractable Viral Marketing 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Gennaro Cordasco
    • 2
  • Luisa Gargano
    • 1
  • Adele A. Rescigno
    • 1
  • Ugo Vaccaro
    • 1
  1. 1.Department of InformaticsUniversity of SalernoFiscianoItaly
  2. 2.Department of PsychologySecond University of NaplesCasertaItaly

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