Please join us for theory lunch this Thursday, where Neel will be giving the following talk.
Title: Near-Optimal $(1+\epsilon)$-Approximate Fully-Dynamic All-Pairs Shortest Paths in Planar Graphs
Joint work with Arnold Filtser, Gramoz Goranci and Maximilian Probst Gutenberg
Abstract:
We
study the fully-dynamic all-pair shortest paths (APSP) problem on
planar graphs: given an $n$-vertex planar graph $G=(V,E)$ undergoing
edge insertions and deletions, the goal is to efficiently process these
updates and support distance and shortest path queries. We give a
$(1+\epsilon)$-approximate dynamic algorithm that supports edge updates
and distance queries in $n^{o(1)}$ time, for any $1/\text{poly}(\log n)
< \epsilon < 1$. Our result is a significant improvement over the
best previously known bound of $\tilde{O}(\sqrt{n})$ on update and query
time due to [Abraham, Chechik, and Gavoille, STOC '12], and bypasses a
$\Omega(\sqrt{n})$ conditional lower-bound on update and query time for
exact fully dynamic planar APSP [Abboud and Dahlgaard, FOCS '16]. The
main technical contribution behind our result is to dynamize the planar
emulator construction due to [Chang, Krauthgamer, Tan, STOC '22].