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Related papers: Classification of Local Optimization Problems in D…

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We consider a class of popular distributed non-convex optimization problems, in which agents connected by a network $\mathcal{G}$ collectively optimize a sum of smooth (possibly non-convex) local objective functions. We address the…

Optimization and Control · Mathematics 2020-01-08 Haoran Sun , Mingyi Hong

Understanding the role of randomness when solving locally checkable labeling (LCL) problems in the LOCAL model has been one of the top priorities in the research on distributed graph algorithms in recent years. For LCL problems in…

Data Structures and Algorithms · Computer Science 2025-10-27 Sebastian Brandt , Fabian Kuhn , Zahra Parsaeian

We study connections between distributed local algorithms, finitary factors of iid processes, and descriptive combinatorics in the context of regular trees. We extend the Borel determinacy technique of Marks coming from descriptive…

In a recent breakthrough result, Balliu et al. [FOCS'19] proved a deterministic $\Omega(\min(\Delta,\log n /\log \log n))$-round and a randomized $\Omega(\min(\Delta,\log \log n/\log \log \log n))$-round lower bound for the complexity of…

Distributed, Parallel, and Cluster Computing · Computer Science 2020-02-20 Sebastian Brandt , Dennis Olivetti

The node-averaged complexity of a distributed algorithm running on a graph $G=(V,E)$ is the average over the times at which the nodes $V$ of $G$ finish their computation and commit to their outputs. We study the node-averaged complexity for…

Distributed, Parallel, and Cluster Computing · Computer Science 2022-08-18 Alkida Balliu , Mohsen Ghaffari , Fabian Kuhn , Dennis Olivetti

Common definitions of the "standard" LOCAL model tend to be sloppy and even self-contradictory on one point: do the nodes update their state using an arbitrary function or a computable function? So far, this distinction has been safe to…

Distributed, Parallel, and Cluster Computing · Computer Science 2026-02-26 Antonio Cruciani , Avinandan Das , Massimo Equi , Henrik Lievonen , Diep Luong-Le , Augusto Modanese , Jukka Suomela

This work studies distributed algorithms for locally optimal load-balancing: We are given a graph of maximum degree $\Delta$, and each node has up to $L$ units of load. The task is to distribute the load more evenly so that the loads of…

Distributed, Parallel, and Cluster Computing · Computer Science 2015-02-17 Laurent Feuilloley , Juho Hirvonen , Jukka Suomela

Balliu et al. (DISC 2020) classified the hardness of solving binary labeling problems with distributed graph algorithms; in these problems the task is to select a subset of edges in a $2$-colored tree in which white nodes of degree $d$ and…

Distributed, Parallel, and Cluster Computing · Computer Science 2023-12-20 Henrik Lievonen , Timothé Picavet , Jukka Suomela

We present a deterministic distributed algorithm that computes a $(2\Delta-1)$-edge-coloring, or even list-edge-coloring, in any $n$-node graph with maximum degree $\Delta$, in $O(\log^7 \Delta \log n)$ rounds. This answers one of the…

Data Structures and Algorithms · Computer Science 2017-04-11 Manuela Fischer , Mohsen Ghaffari , Fabian Kuhn

We consider a distributed convex optimization problem in a network which is time-varying and not always strongly connected. The local cost function of each node is affected by some stochastic process. All nodes of the network collaborate to…

Optimization and Control · Mathematics 2021-05-27 Wenjie Li , Mohamad Assaad

The celebrated Time Hierarchy Theorem for Turing machines states, informally, that more problems can be solved given more time. The extent to which a time hierarchy-type theorem holds in the distributed LOCAL model has been open for many…

Distributed, Parallel, and Cluster Computing · Computer Science 2017-04-24 Yi-Jun Chang , Seth Pettie

Locally Checkable Labeling (LCL) problems include essentially all the classic problems of $\mathsf{LOCAL}$ distributed algorithms. In a recent enlightening revelation, Chang and Pettie [arXiv 1704.06297] showed that any LCL (on bounded…

Data Structures and Algorithms · Computer Science 2017-05-17 Manuela Fischer , Mohsen Ghaffari

The \emph{Steiner tree} problem is one of the fundamental and classical problems in combinatorial optimization. In this paper, we study this problem in the $\mathcal{CONGESTED}$ $\mathcal{CLIQUE}$ model of distributed computing and present…

Distributed, Parallel, and Cluster Computing · Computer Science 2019-07-31 Parikshit Saikia , Sushanta Karmakar

Local search is a fundamental optimization technique that is both widely used in practice and deeply studied in theory, yet its computational complexity remains poorly understood. The traditional frameworks, PLS and the standard algorithm…

Computational Complexity · Computer Science 2026-01-05 Robert Ganian , Hung P. Hoang , Christian Komusiewicz , Nils Morawietz

We settle the complexity of the $(\Delta+1)$-coloring and $(\Delta+1)$-list coloring problems in the CONGESTED CLIQUE model by presenting a simple deterministic algorithm for both problems running in a constant number of rounds. This…

Data Structures and Algorithms · Computer Science 2020-09-15 Artur Czumaj , Peter Davies , Merav Parter

By prior work, we have many results related to distributed graph algorithms for problems that can be defined with local constraints; the formal framework used in prior work is locally checkable labeling problems (LCLs), introduced by Naor…

Distributed, Parallel, and Cluster Computing · Computer Science 2024-07-09 Alkida Balliu , Mohsen Ghaffari , Fabian Kuhn , Augusto Modanese , Dennis Olivetti , Mikaël Rabie , Jukka Suomela , Jara Uitto

The question of 'what can be computed locally?' lies at the heart of distributed computing in networks. As established in Naor and Stockmeyer's seminal paper (STOC 1993), this question is undecidable, even for graph problems whose solutions…

Data Structures and Algorithms · Computer Science 2026-02-05 Lélia Blin , Fedor V. Fomin , Pierre Fraigniaud , Sylvain Gay , Petr A. Golovach , Pedro Montealegre , Ivan Rapaport , Ioan Todinca

Very recently, Khoury and Schild [FOCS 2025] showed that any randomized LOCAL algorithm that solves maximal matching requires $\Omega(\min\{\log \Delta, \log_\Delta n\})$ rounds, where $n$ is the number of nodes in the graph and $\Delta$ is…

Distributed, Parallel, and Cluster Computing · Computer Science 2025-11-21 Alkida Balliu , Filippo Casagrande , Francesco d'Amore , Dennis Olivetti

This paper studies lower bounds for fundamental optimization problems in the CONGEST model. We show that solving problems exactly in this model can be a hard task, by providing $\tilde{\Omega}(n^2)$ lower bounds for cornerstone problems,…

Data Structures and Algorithms · Computer Science 2019-05-27 Nir Bachrach , Keren Censor-Hillel , Michal Dory , Yuval Efron , Dean Leitersdorf , Ami Paz

This paper studies a class of distributed optimization problems with coupled equality constraints in networked systems. Many existing distributed algorithms rely on solving local subproblems via the $\operatorname{argmin}$ operator in each…

Optimization and Control · Mathematics 2025-11-26 Chenyang Qiu , Zongli Lin