学术报告
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Bounded Topology of Complete Manifolds with Nonnegative Ricci Curvature and Q...In this talk, I will introduce the main results about the bounded topology of complete manifolds with nonnegative Ricci curvature and quadratically asymptotically nonnegative curvature, which will include two parts. In the first part, I will outline the results of showing such manifolds to be of finite topological type provided with some additional conditions. In the other part, I will explain the constuction of some interesting examples with such curvature conditions and infinite topology.蒋辉宏 讲师 (上海师范大学)腾讯会议室2021年11月9日(星期二) 10:00-11:30
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Area Comparison of Hypersurfaces in Space FormsMean curvature is one of the most fundamental extrinsic curvature in the theory of submanifold. A natural question is that wether mean curvature can control the area of hypersurfaces. In this talk, we discuss the area comparison with respect to mean curvature for hypersurfaces in space forms. This is a joint work with Professor Sun Jun in Wuhan University.袁伟 副教授 (中山大学)腾讯会议室2021年11月5日(星期五) 9:00-10:30
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Big Hankel Operators on Hardy Spaces of Strongly Pseudoconvex DomainsIn this article, we investigate the (big) Hankel operators H_f on Hardy spaces of bounded strongly pseudoconvex domains in C^n We also give a necessary and sufficient condition for boundedness of Hankel operator H_...江良英 副教授 (上海立信会计金融学院)腾讯会议室2021年10月31日(星期日) 9:00-10:00
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The Reduced Expressions in a Coxeter System with a Strictly Complete Coxeter ...Let $(W,S)$ be a Coxeter system with a strictly complete Coxeter graph. The present talk is concerned with the set $\Red(z)$ of all reduced expressions for any $z\in W$. By associating each bc-expression to a certain symbol, we describe the set $\Red(z)$ and compute its cardinal $|\Red(z)|$ in terms of symbols. An explicit formula for $|\Red(z)|$ is deduced, where the Fibonacci numbers play a crucial role.时俭益 教授(华东师范大学)致远楼108室2021年11月4日(星期四)下午4:00--5:00
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Global Existence and Analyticity of Viscous Capillary Compressible FluidsWe are concerned with a system of equations governing the evolution of isothermal, viscous and capillary compressible fluids, which is used as the phase transition model. In the case of zero sound speed, it is found that the linearized system admits a purely parabolic structure. Consequently, one can establish the global-in-time existence and Gevrey analyticity of Lp solutions in hybrid Besov spaces, which improves the prior L2 bounds on the low frequencies of density and velocity due to acoustic waves. The proof mainly relies on new Besov (-Gevrey) estimates for product and composition of functions.徐江 教授 (南京航空航天大学)致远楼108室2021年11月1日(星期一) 10:00-11:00
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A Deformed Hermitian Yang-Mills FlowRecently, the deformed Hermitian Yang-Mills equation has been extensively studied. In this talk, we introduce a deformed Hermitian Yang-Mills flow in the supercritical case on a compact Kähler manifold. Under a suitable condition on the subsolution, we show the longtime existence of the flow and we prove that the solution converges exponentially to the solution of the elliptic deformed Hermitian Yang-Mills equation which has been solved by Collins-Jacob-Yau by the method of continuity. This is a joint work with Professor Jixiang Fu.张德凯 讲师 (上海大学)宁静楼117室2021年11月29日 13:30-15:00
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On the Gaussian Minkowski ProblemWe would like to talk about the Minkowski problem for Gaussian surface area measure. Both the uniqueness and existence results are investigated. This is a joint work with Huang Yong and Zhao Yiming.席东盟 副教授 (上海大学)宁静楼117室2021年11月27日 10:00-11:30
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On a Family of Integral Operators on the BallIn this work, we transform the equation in the upper half space first studied by Caffarelli and Silvestre to an equation in the Euclidean unit ball $\mathbb{B}^n$. We identify the Poisson kernel for the equation in the unit ball. Using the Poisson kernel, we define the extension operator. We prove an extension inequality in the limit case and prove the uniqueness of the extremal functions in the limit case using the method of moving spheres. In addition we offer an interpretation of the limit case inequality as a conformally invariant generalization of Carleman's inequality.田闻川 博士 (加州大学圣芭芭拉分校)腾讯会议室2021年10月26日 9:00-11:00