Further Unifying the Landscape of Cell Probe Lower Bounds

TL;DR

This paper refines the connection between static and dynamic data structure lower bounds by providing a lossless reduction from reachability in the butterfly graph to dynamic marked ancestor, unifying the lower bounds landscape.

Contribution

It introduces a new lossless reduction that fully captures the lower bounds for dynamic marked ancestor from reachability in the butterfly graph.

Findings

Establishes a lossless reduction to dynamic marked ancestor

Unifies static and dynamic data structure lower bounds

Enables derivation of tight lower bounds from a single seed problem

Abstract

In a landmark paper, P\v{a}tra\c{s}cu demonstrated how a single lower bound for the static data structure problem of reachability in the butterfly graph, could be used to derive a wealth of new and previous lower bounds via reductions. These lower bounds are tight for numerous static data structure problems. Moreover, he also showed that reachability in the butterfly graph reduces to dynamic marked ancestor, a classic problem used to prove lower bounds for dynamic data structures. Unfortunately, P\v{a}tra\c{s}cu's reduction to marked ancestor loses a $\lg \lg n$ factor and therefore falls short of fully recovering all the previous dynamic data structure lower bounds that follow from marked ancestor. In this paper, we revisit P\v{a}tra\c{s}cu's work and give a new lossless reduction to dynamic marked ancestor, thereby establishing reachability in the butterfly graph as a single seed problem from which a range of tight static and dynamic data structure lower bounds follow.