Title
Direct product via round-preserving compression
Abstract
We obtain a strong direct product theorem for two-party bounded round communication complexity. Let sucr(μ,f,C) denote the maximum success probability of an r-round communication protocol that uses at most C bits of communication in computing f(x,y) when (x,y)~μ. Jain et al. [12] have recently showed that if ${\sf suc}_{r}(\mu,f,C) \leq \frac{2}{3}$ and $T\ll (C-\Omega (r^2)) \cdot\frac{n}{r}$, then ${\sf suc}_r(\mu^n,f^n,T)\leq \exp(-\Omega(n/r^2))$. Here we prove that if ${\sf suc}_{7r}(\mu,f,C) \leq \frac{2}{3}$ and T≪(C−Ω(r logr)) ·n then ${\sf suc}_{r}(\mu^n,f^n,T)\leq\exp(-\Omega(n))$. Up to a logr factor, our result asymptotically matches the upper bound on suc7r(μn,fn,T) given by the trivial solution which applies the per-copy optimal protocol independently to each coordinate. The proof relies on a compression scheme that improves the tradeoff between the number of rounds and the communication complexity over known compression schemes.
Year
DOI
Venue
2013
10.1007/978-3-642-39206-1_20
ICALP
Keywords
DocType
Volume
sf suc,maximum success probability,c bit,r-round communication protocol,direct product,result asymptotically,logr factor,per-copy optimal protocol,round-preserving compression,two-party bounded round communication,communication complexity,compression scheme
Journal
20
ISSN
Citations 
PageRank 
0302-9743
11
0.81
References 
Authors
22
4
Name
Order
Citations
PageRank
Mark Braverman181061.60
Anup Rao258132.80
omri weinstein3496.47
Amir Yehudayoff453043.83