Improved approximation algorithms for broadcast scheduling
Nikhil Bansal, Don Coppersmith, et al.
SODA 2006
The complex quadratic form z′ Pz, where z is a fixed vector in Cn and z′ is its transpose, and P is any permutation matrix, is shown to be a convex combination of the quadratic forms z′ Pσz, where Pσ denotes the symmetric permutation matrices. We deduce that the optimal probability density associated to the chiral index of a sample from a bivariate distribution is symmetric. This result is used to locate the upper bound of the chiral index of any bivariate distribution in the interval [1 - 1/π, 1 - 1/2π]. © 2005 Académie de sciences. Published by Elsevier SAS. All rights reserved.
Nikhil Bansal, Don Coppersmith, et al.
SODA 2006
Don Coppersmith
Journal of Complexity
Inder Gopal, Don Coppersmith, et al.
IEEE Transactions on Communications
Don Coppersmith, Nick Howgrave-Graham, et al.
Journal of Discrete Algorithms