 
Summary: A 2Source AlmostExtractor for Linear Entropy
Anup Rao,1
School of Mathematics, Institute for Advanced Study
arao@ias.edu
Abstract. We give an explicit construction of a function that is almost
a 2source extractor for linear entropy, it is a condenser where the output
has almost full entropy. Given 2 sources with entropy n, the output of
the condenser is a distribution on mbit strings that is close to having
minentropy m  poly(log(1/), 1/), where here m is linear in n.
1 Introduction
This paper is about constructing efficiently computable 2source extractors.
These are efficiently computable functions of the type Ext : {0, 1}n
× {0, 1}n
{0, 1}m
with the property that for any 2 independent distributions X, Y , each
with entropy1
k, the output Ext(X, Y ) is close to uniform. Another way to view
this object is as a coloring of the edges of the N × N complete bipartite graph
with M colors that guarantees that in every K ×K complete bipartite subgraph,
