From Independence To Expansion And Back Again

Christiani Tobias, Pagh Rasmus, Thorup Mikkel. Arxiv 2015

[Paper]    
ARXIV FOCS Graph Independent

We consider the following fundamental problems: (1) Constructing $k$-independent hash functions with a space-time tradeoff close to Siegel’s lower bound. (2) Constructing representations of unbalanced expander graphs having small size and allowing fast computation of the neighbor function. It is not hard to show that these problems are intimately connected in the sense that a good solution to one of them leads to a good solution to the other one. In this paper we exploit this connection to present efficient, recursive constructions of $k$-independent hash functions (and hence expanders with a small representation). While the previously most efficient construction (Thorup, FOCS 2013) needed time quasipolynomial in Siegel’s lower bound, our time bound is just a logarithmic factor from the lower bound.

Similar Work

• Lower Bounds On Time-space Trade-offs For Approximate Near Neighbors
• Optimal Hashing-based Time-space Trade-offs For Approximate Near Neighbors
• Tight Lower Bounds For Data-dependent Locality-sensitive Hashing
• Constructing Error-correcting Binary Codes Using Transitive Permutation Groups