时 间: 2010年7月15日（周四）下午3:00

地 点: 清华大学高等研究院 科学馆322报告厅

题 目: Identity Testing and Sign Determination of Algebraic Numbers

报 告 人: Qi Cheng（程岐）University of Oklahoma

报告摘要:Given a real algebraic number, is there an efficient procedure to decide whether it is greater than zero or not? The problem is poorly understood when the algebraic number has high extension degree. In this talk, we will show that the problem is related to several open problems in computer science and mathematics, such as lower bounds on exponential sums in number theory, sum of square roots problem in computational geometry and polynomial identity testing problem in computational complexity. We will also present some partial results on these problems.