Let Y be a smooth projective surface defined over an algebraically closed field k with char k>2, and let $/pi:X->Y$ be a double covering branched along a smooth divisor. We show that the tangent bundle T_X is stable with respect to $/pi^*{H}$ if the tangent bundle T_Y is semi-stable with respect to some ample line bundle H on Y.

Many computational science and data analysis techniques lead to optimizing Rayleigh-Quotient (RQ) and RQ-type objective functions,such as computing excitation states (energies) of electronic structures,robust classification to handle uncertainty and constraineddata clustering to incorporate a prior information. In this talk,we will discuss origins of RQ optimizations, variational principles,and reformulations to algebraic eigenvalue problems. We will show how to exploit underlying properties of eigenvalue problems for design reliable and fast eigensolvers, and illustrate the efficacy of these eigensolvers in electronic structure calculations and constrained image segmentations.

Calogero-Sutherland模型是一个一维的量子多体完全可积系统。Navier-Stokes方程是流体力学中最基本的微分方程。我们将讲解超几何函数与Calogero-Sutherland模型的联系，并介绍Navier-Stokes方程的对称变换群，非对称解法和活动标架解法

Recent advances in networking technologies, especially wireless networks, generate a new paradigm of control and filtering for industrial systems via networks. Traditionally, such systems are controlled and estimated by independent networks, which are designed with enough bandwidth and resources. In network environments, shared wired and wireless networks are utilized to connect industrial systems and controllers/filters. In this new framework, bandwidth and resource constraints should be taken into account in controller/filter design, and real-time becomes increasingly important to control and filtering.

We introduce a new family of symmetric functions via the Jacobi-Trudi identity to cover the orthogonal or symplectic Schur functions as well as the Okounkov-Olshanski shifted symmetric functions. It is proved that they all can be treated as the usual Schur functions, and their vertex operator realization and Giambelli identities are given by using the boson-fermion correspondence.

本讲将沿一条主线介绍多复变的简史、基本内容及新近进展

In this talk, after I recall classical finite elements of high order partial differential equations, I will present some new results in this direction, including a family of first order Hm conforming finite elements on tensor product grids in any dimension, a family of first order Hm nonconforming finite elements on triangular grids in two dimension, and two second order H2 nonconforming finite elements, and some new theories for error estimates.

题目：模表示论新进展报告人：张继平教授（杰青、北京大学国际数学中心执行副主任）时间：2017年4月6日 16:00-17:00地点：致远楼107室报告人简介：张继平，北京大学教授、博士生导师、国家杰出青年基金获得者、长江学者奖励计划特聘教授、国家级有突出贡献的中青年专家、全国优秀科技工作者、全国五一劳动奖章获得者、北京市十大杰出青年，他曾获国家自然科学奖、教育部科技进步一等奖、“求是”杰出青年学者奖、中国青年科学家...