Worst-Case and Average-Case Hardness of Hypercycle and Database Problems

Cheng-Hao Fu; Andrea Lincoln; Rene Reyes

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arXiv · 2504.18640

Worst-Case and Average-Case Hardness of Hypercycle and Database Problems

Cheng-Hao Fu·Andrea Lincoln·Rene Reyes

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Abstract

In this paper we present tight lower-bounds and new upper-bounds for hypergraph and database problems. We give tight lower-bounds for finding minimum hypercycles. We give tight lower-bounds for a substantial regime of unweighted hypercycle. We also give a new faster algorithm for longer unweighted hypercycles. We give a worst-case to average-case reduction from detecting a subgraph of a hypergraph in the worst-case to counting subgraphs of hypergraphs in the average-case. We demonstrate two applications of this worst-case to average-case reduction, which result in average-case lower bounds for counting hypercycles in random hypergraphs and queries in average-case databases. Our tight upper and lower bounds for hypercycle detection in the worst-case have immediate implications for the average-case via our worst-case to average-case reductions.

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Cheng-Hao Fu, Andrea Lincoln, Rene Reyes. 2025-04-25. Worst-Case and Average-Case Hardness of Hypercycle and Database Problems. https://arxiv.org/abs/2504.18640

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