@inproceedings{738daedbe11a4b3cb2bc89ebba74ac56,
title = "Near-quadratic lower bounds for two-pass graph streaming algorithms",
abstract = "We prove that any two-pass graph streaming algorithm for the s-t reachability problem in n-vertex directed graphs requires near-quadratic space of n{2-o(1)} bits. As a corollary, we also obtain near-quadratic space lower bounds for several other fundamental problems including maximum bipartite matching and (approximate) shortest path in undirected graphs. Our results collectively imply that a wide range of graph problems admit essentially no non-trivial streaming algorithm even when two passes over the input is allowed. Prior to our work, such impossibility results were only known for single-pass streaming algorithms, and the best two-pass lower bounds only ruled out o(n{7/6}) space algorithms, leaving open a large gap between (trivial) upper bounds and lower bounds.",
keywords = "Graph streaming, communication complexity, multi pass streaming lower bounds, s-t reachability",
author = "Sepehr Assadi and Ran Raz",
note = "Publisher Copyright: {\textcopyright} 2020 IEEE.; 61st IEEE Annual Symposium on Foundations of Computer Science, FOCS 2020 ; Conference date: 16-11-2020 Through 19-11-2020",
year = "2020",
month = nov,
doi = "10.1109/FOCS46700.2020.00040",
language = "English (US)",
series = "Proceedings - Annual IEEE Symposium on Foundations of Computer Science, FOCS",
publisher = "IEEE Computer Society",
pages = "342--353",
booktitle = "Proceedings - 2020 IEEE 61st Annual Symposium on Foundations of Computer Science, FOCS 2020",
address = "United States",
}