Title
Infectious Random Walks
Abstract
We study the dynamics of information (or virus) dissemination by $m$ mobile agents performing independent random walks on an $n$-node grid. We formulate our results in terms of two scenarios: broadcasting and gossiping. In the broadcasting scenario, the mobile agents are initially placed uniformly at random among the grid nodes. At time 0, one agent is informed of a rumor and starts a random walk. When an informed agent meets an uninformed agent, the latter becomes informed and starts a new random walk. We study the broadcasting time of the system, that is, the time it takes for all agents to know the rumor. In the gossiping scenario, each agent is given a distinct rumor at time 0 and all agents start random walks. When two agents meet, they share all rumors they are aware of. We study the gossiping time of the system, that is, the time it takes for all agents to know all rumors. We prove that both the broadcasting and the gossiping times are $\tilde\Theta(n/\sqrt{m})$ w.h.p., thus achieving a tight characterization up to logarithmic factors. Previous results for the grid provided bounds which were weaker and only concerned average times. In the context of virus infection, a corollary of our results is that static and dynamically moving agents are infected at about the same speed.
Year
Venue
Keywords
2010
Clinical Orthopaedics and Related Research
random walk,data structure,discrete mathematics,mobile agent
Field
DocType
Volume
Discrete mathematics,Broadcasting,Random walk,Computer science,Rumor,Gossip,Logarithm,Corollary,Grid
Journal
abs/1007.1
Citations 
PageRank 
References 
4
0.44
9
Authors
4
Name
Order
Citations
PageRank
Alberto Pettarin1372.37
Andrea Pietracaprina211813.77
Geppino Pucci344350.49
Eli Upfal44310743.13