Abstract
Consider a distributed non-convex optimization problem, in which a number of agents connected by a network mathcal{G} collectively optimize a sum of smooth and non-convex local objective functions. We address the following important question: For a class of unconstrained problems, if only local gradient information is available, what is the fastest rate that distributed algorithms can achieve, and how to achieve those rates. We perform a lower bound analysis for a class of first-order distributed methods which only utilizes local gradient information. We show that in the worst-case it takes at least mathcal{O}(1/sqrt{xi(mathcal{G})}times L/epsilon) iterations to achieve certain epsilon-solution, where xi(mathcal{G}) represents the spectrum gap of the graph Laplacian matrix, and L is some Lipschitz constant. Further, for a general problem class, we propose rate-optimal methods whose rates match the lower bounds (up to a polylog factor). To the best of our knowledge, this is the first time that lower rate bounds and optimal methods have been developed for distributed non-convex optimization problems.
Original language | English (US) |
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Title of host publication | Conference Record of the 52nd Asilomar Conference on Signals, Systems and Computers, ACSSC 2018 |
Editors | Michael B. Matthews |
Publisher | IEEE Computer Society |
Pages | 38-42 |
Number of pages | 5 |
ISBN (Electronic) | 9781538692189 |
DOIs | |
State | Published - Jul 2 2018 |
Event | 52nd Asilomar Conference on Signals, Systems and Computers, ACSSC 2018 - Pacific Grove, United States Duration: Oct 28 2018 → Oct 31 2018 |
Publication series
Name | Conference Record - Asilomar Conference on Signals, Systems and Computers |
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Volume | 2018-October |
ISSN (Print) | 1058-6393 |
Conference
Conference | 52nd Asilomar Conference on Signals, Systems and Computers, ACSSC 2018 |
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Country/Territory | United States |
City | Pacific Grove |
Period | 10/28/18 → 10/31/18 |
Bibliographical note
Funding Information:This work was supported in part by the National Science Foundation under Grants CMMI-1727757
Funding Information:
H. Sun and M. Hong are with the Department of Electrical and Computer Engineering (ECE), University of Minnesota, Minneapolis, MN 55414, USA. Email: {sun00111,mhong}@umn.edu This work was supported in part by the National Science Foundation under Grants CMMI-1727757, and in part by the Air Force Office of Scientific Research under Grant 15RT0767.
Publisher Copyright:
© 2018 IEEE.