致远楼 107 摘要： We will establish a bijective correspondence between finite type associative cones in $/R^7$ and their spectral data, which consists of a hexagonal algebraic curve and a planar flow of line bundles in its Jacobian. We characterize the spectral data by identifying various symmetries on them. We prove generic smoothness of these spectral curves, compute their genus, and compute the dimension of the moduli of such curves. Then we identify a Prym-Tjurin subtorus of the Jacobian, in which the direction of the flow must lie, and compute its dimension. Finally we characterize finite type special Lagrangian cones in $/C^3$ as a subclass of such associative cones in terms of the spectral data. These computations are mainly motivated by Hitchin's recent work on G_2 spectral curves and Langland duality.

In this talk, I will introduce the notion of symmetries and then I will discuss r-dressing and the construction of trinoids.

Yule-Walker estimators are constructed for autoregressive coefficients based on the observed time series that contains an unknown trend function and an autoregressive error term. The trend function is estimated by means of B-spline or local polynomial smoothing and then subtracted from the observations. The Yule-Walker estimators are then obtained from the residual sequence, which enjoy oracle efficiency, i.e., they are asymptotically as efficient as if the true trend function were known. The performance of the estimator is illustrated by simulation studies and real data analysis

报告人：郑惠恒教授（帝国理工）题目：Wealth vs Risk in a Continuous Time Model时间：2012年4月12日，星期四下午1：00—2：00地点：数学系致远楼107欢迎各位参加

报 告 人：马力 教授（河南师范大学数学与信息科学学院）报告题目：2-dimensional Ricci Flow报告时间：2012年4月6日（周五）下午3:00-4:00报告地点：致远楼107室欢迎广大师生参加！2012-4-

题 目：Twisted Calabi-Yau Algebras and AS-regular (Hopf) algebras报告人：吴泉水 教授（复旦大学数学学院院长）时 间：4月6日（周五），下午数学系致远楼107教室 4:30-5:30地 点：数学系致远楼107教

报告人：倪维明教授（美国Minnesota大学 华东师大）题目： Diffusion and Spatial Heterogeneity时间：2012年4月1日，星期日下午3：30—4：30地点：数学系致远楼107欢迎各位参加

报告人：郑惠恒教授（帝国理工）题目：A Generic First Passage Model with Random Barrier and Information Feedback for Correlated Defaults时间：2012年3月31日，星期六下午3：30—4：30地点：数学系致远楼107欢迎各位参加

报告人：姜翠波教授 （上海交通大学数学系）报告题目：正定格顶点算子代数的不动点子代数及表示时间： 2012年4月5日（周四）下午 4:30-5:30地点： 数学系 （致远楼）107教室欢迎广大师生参加数学系、数学

报告人：芮和兵教授（华东师大数学系，杰青）报告题目：BMW代数及其相关问题时间： 2012年3月30日（周五）下午 4:30-5:30地点： 数学系 （致远楼）107教室欢迎广大师生参加数学系、数学