--- res: bibo_abstract: - "Let G be a graph on n nodes. In the stochastic population protocol model, a collection of n indistinguishable, resource-limited nodes collectively solve tasks via pairwise interactions. In each interaction, two randomly chosen neighbors first read each other’s states, and then update their local states. A rich line of research has established tight upper and lower bounds on the complexity of fundamental tasks, such as majority and leader election, in this model, when G is a clique. Specifically, in the clique, these tasks can be solved fast, i.e., in n polylog n pairwise interactions, with high probability, using at most polylog n states per node.\r\nIn this work, we consider the more general setting where G is an arbitrary regular graph, and present a technique for simulating protocols designed for fully-connected networks in any connected regular graph. Our main result is a simulation that is efficient on many interesting graph families: roughly, the simulation overhead is polylogarithmic in the number of nodes, and quadratic in the conductance of the graph. As a sample application, we show that, in any regular graph with conductance φ, both leader election and exact majority can be solved in φ^{-2} ⋅ n polylog n pairwise interactions, with high probability, using at most φ^{-2} ⋅ polylog n states per node. This shows that there are fast and space-efficient population protocols for leader election and exact majority on graphs with good expansion properties. We believe our results will prove generally useful, as they allow efficient technology transfer between the well-mixed (clique) case, and the under-explored spatial setting.@eng" bibo_authorlist: - foaf_Person: foaf_givenName: Dan-Adrian foaf_name: Alistarh, Dan-Adrian foaf_surname: Alistarh foaf_workInfoHomepage: http://www.librecat.org/personId=4A899BFC-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0003-3650-940X - foaf_Person: foaf_givenName: Rati foaf_name: Gelashvili, Rati foaf_surname: Gelashvili - foaf_Person: foaf_givenName: Joel foaf_name: Rybicki, Joel foaf_surname: Rybicki foaf_workInfoHomepage: http://www.librecat.org/personId=334EFD2E-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0002-6432-6646 bibo_doi: 10.4230/LIPIcs.OPODIS.2021.14 bibo_volume: 217 dct_date: 2022^xs_gYear dct_isPartOf: - http://id.crossref.org/issn/1868-8969 - http://id.crossref.org/issn/9783959772198 dct_language: eng dct_publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik@ dct_title: Fast graphical population protocols@ ...