学 术 报 告 （二）

More general talk

报告题目：3264: the real, complete story of plane conics

报告人：Frank Sottile教授, Texas A&M University

报告时间：2015年8月13日（星期四）9:30--11:00

报告地点：创新园大厦A1101

校内联系人：朱春钢       Email: cgzhu@

报告内容：

In 1848 Steiner asserted that, given 5 general conics in the plane (ellipses, hyperbolae, or parabolae), there are exactly 7776 (=6^5) other conics tangent to the given 5.  He was unfortunately wrong and the correct answer of 3264 (=2^5 * 102) was given by Chasles in 1864. More recently, Fulton, and Ronga, Tognoli, and Vust have separately shown it is possible to choose 5 real conics so that each of the 3264 tangent conics are also real.

While this talk will explain the obvious numerological questions (where do 7776 and 3264 come from?), my goal is to convince you that 3264 is the correct number. This explanation will also show why this works over the real numbers.

报告人简介：

 Frank Sottile在美国芝加哥大学获得博士学位，目前为美国Texas A&M大学数学系教授，主要研究方向为代数几何理论与应用、代数组合、离散与计算几何等。Sottile教授目前担任期刊SIAM J. Discrete Math.、Can. J. Math.、Can. Math. Bull.与Am. Math. Mon.副主编，曾任SIAM Activity Group on Algebraic Geometry首任主席。2012年，Sottile教授当选为美国数学会(AMS)首任会士(Fellow)。Sottile教授获得包括NSF CAREER Award在内的多项基金资助，在J. AMS, Bull. AMS, Tran. AMS, FoCM, ACM TOG, ACM T Math. Software, Adv. Math., Am. J. Math, Duke J. Math.等著名期刊发表论文100余篇，2011年由AMS出版专著《Real Solutions to Equations From Geometry》。