Gathering Synchronous Robots in Graphs: From General Properties to Dense and Symmetric Topologies

  • Serafino Cicerone
  • Gabriele Di Stefano
  • Alfredo NavarraEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11639)


The Gathering task by means of a swarm of robots disposed on the vertices of a graph requires robots to move toward a common vertex from where they do not move anymore.

When dealing with very weak robots in terms of capabilities, considering synchronous or asynchronous settings may heavily affect the feasibility of the problem. In fact, even though dealing with asynchronous robots in general requires more sophisticated strategies with respect to the synchronous counterpart, sometimes it comes out that asynchronous robots simply cannot solve the problem whereas synchronous robots can. We study general properties of graphs that can be exploited in order to accomplish the gathering task in the synchronous setting, obtaining an interesting sufficient condition for the feasibility, applicable to any topology. We then consider dense and symmetric graphs like complete and complete bipartite graphs where asynchronous robots cannot solve much. In such topologies we fully characterize the solvability of the gathering task in the synchronous setting by suitably combining some strategies arising by the general approach with specific techniques dictated by the considered topologies.


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Serafino Cicerone
    • 1
  • Gabriele Di Stefano
    • 1
  • Alfredo Navarra
    • 2
    Email author
  1. 1.Dipartimento di Ingegneria e Scienze dell’Informazione e MatematicaUniversità degli Studi dell’AquilaL’AquilaItaly
  2. 2.Dipartimento di Matematica e InformaticaUniversità degli Studi di PerugiaPerugiaItaly

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