报告摘要：

  In this talk we shall present several recent results on the following complex quadratic optimization model: maximize $z^H Q z$, subject to $z \in C^n, z_k^m=1, k=1,...,n$, where $C^n$ is the n-dimensional complex Euclidean space, and $m\ge 2$ is an integer and is a parameter of the model. We consider three cases, where the problem remains NP-hard, and discuss approximation algorithms with provable worst-case approximation ratios. These three cases are: (1) $Q$ is Hermitian positive semidefinite; (2) the trace of $Q$ is zero; (3) $Q$ can be partitioned into 2 by 2 block matrices with the two diagonal sub-matrices being zero.

报告时间： 2005年11月8日(周二) 下午3:30--4:30

报告地点：科技综合楼三层311报告厅