  Under the auspices of the Computational Complexity Foundation (CCF)     REPORTS > KEYWORD > SIGN-RANK:
Reports tagged with Sign-rank:
TR07-112 | 25th September 2007
Alexander A. Sherstov

#### Unbounded-Error Communication Complexity of Symmetric Functions

The sign-rank of a real matrix M is the least rank
of a matrix R in which every entry has the same sign as the
corresponding entry of M. We determine the sign-rank of every
matrix of the form M=[ D(|x AND y|) ]_{x,y}, where
D:{0,1,...,n}->{-1,+1} is given and ... more >>>

TR08-016 | 26th February 2008
Alexander Razborov, Alexander A. Sherstov

#### The Sign-Rank of AC^0

The sign-rank of a matrix A=[A_{ij}] with +/-1 entries
is the least rank of a real matrix B=[B_{ij}] with A_{ij}B_{ij}>0
for all i,j. We obtain the first exponential lower bound on the
sign-rank of a function in AC^0. Namely, let
f(x,y)=\bigwedge_{i=1}^m\bigvee_{j=1}^{m^2} (x_{ij}\wedge y_{ij}).
We show that the matrix [f(x,y)]_{x,y} has ... more >>>

TR16-075 | 9th May 2016
Mark Bun, Justin Thaler

#### Improved Bounds on the Sign-Rank of AC$^0$

Revisions: 1

The sign-rank of a matrix $A$ with entries in $\{-1, +1\}$ is the least rank of a real matrix $B$ with $A_{ij} \cdot B_{ij} > 0$ for all $i, j$. Razborov and Sherstov (2008) gave the first exponential lower bounds on the sign-rank of a function in AC$^0$, answering an ... more >>>

TR22-079 | 25th May 2022
Hamed Hatami, Pooya Hatami, William Pires, Ran Tao, Rosie Zhao

#### Lower Bound Methods for Sign-rank and their Limitations

The sign-rank of a matrix $A$ with $\pm 1$ entries is the smallest rank of a real matrix with the same sign pattern as $A$. To the best of our knowledge, there are only three known methods for proving lower bounds on the sign-rank of explicit matrices: (i) Sign-rank is ... more >>>

TR22-130 | 15th September 2022
Hamed Hatami, Kaave Hosseini, Xiang Meng

#### A Borsuk-Ulam lower bound for sign-rank and its application

We introduce a new topological argument based on the Borsuk-Ulam theorem to prove a lower bound on sign-rank.

This result implies the strongest possible separation between randomized and unbounded-error communication complexity. More precisely, we show that for a particular range of parameters, the randomized communication complexity of ... more >>>

TR23-050 | 18th April 2023
Manasseh Ahmed, TsunMing Cheung, Hamed Hatami, Kusha Sareen

#### Communication complexity of half-plane membership

We study the randomized communication complexity of the following problem. Alice receives the integer coordinates of a point in the plane, and Bob receives the integer parameters of a half-plane, and their goal is to determine whether Alice's point belongs to Bob's half-plane.

This communication task corresponds to determining ... more >>>

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