A Faster Algorithm for Finding Tarski Fixed Points



Fearnley, John, Pálvölgyi, Dömötör and Savani, Rahul ORCID: 0000-0003-1262-7831
(2022) A Faster Algorithm for Finding Tarski Fixed Points ACM Transactions on Algorithms, 18 (3). pp. 1-23. ISSN 1549-6325, 1549-6333

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Abstract

Dang et al. have given an algorithm that can find a Tarski fixed point in a k -dimensional lattice of width n using O (log k n ) queries [ 2 ]. Multiple authors have conjectured that this algorithm is optimal [ 2 , 7 ], and indeed this has been proven for two-dimensional instances [ 7 ]. We show that these conjectures are false in dimension three or higher by giving an O (log 2 n ) query algorithm for the three-dimensional Tarski problem. We also give a new decomposition theorem for k -dimensional Tarski problems which, in combination with our new algorithm for three dimensions, gives an O (log 2 ⌈k/3⌉ n ) query algorithm for the k -dimensional problem.

Item Type: Article
Divisions: Faculty of Science & Engineering > School of Electrical Engineering, Electronics and Computer Science
Depositing User: Symplectic Admin
Date Deposited: 07 Mar 2022 08:48
Last Modified: 06 Dec 2024 20:55
DOI: 10.1145/3524044
Related Websites:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3150185
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