学术报告
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Conservation law for harmonic mappings in higher dimensionsIt has been a longstanding open problem to find a direct conservation law for harmonic mappings into manifolds. In the late 1980s, Chen and Shatah independently found a conservation law for weakly harmonic maps into spheres, which can be interpreted by Noether's theorem. This leads to Helein's celebrated regularity theorem on weakly harmonic maps from surfaces. For general target manifolds, Riviere discovered a direct conservation law in two dimension in 2007, allowing him to solve two well-known conjectures of Hildebrandt and Heinz. As observed by Riviere-Struwe in 2008, due to lack of Wente's lemma, Riviere's approach does not extend to higher dimensions. In a recent joint work with Chang-Lin Xiang, we successfully found a conservation law for a class of weakly harmonic maps into general closed manifolds in higher dimensions.郭常予 教授(山东大学)腾讯会议室2022年7月4日(星期一) 9:10-10:10
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Moments and equidistributions of multiplicative analogues of KloostermanIn this talk, we consider a family of character sums as multiplicative analogues of Kloosterman sums. We establish asymptotic formulae for any real (positive) moments of the above character sum as the character runs over all non-trivial multiplicative characters mod p, confirming a conjecture of Professor Wenpeng Zhang from 2002. Moreover, an arcsine law will be established as a consequence of the method of moments in probability theory. The arguments, amongst other tools, also allow us to obtain asymptotic formulae for moments of such character sums weighted by special L-values (at 1/2 and 1). The tools will include Gauss sums, hyper-Kloosterman sums, as well as a recent estimate for bilinear forms with general algebraic trace functions due to Fouvry, Kowalski and Michel.郗平 教授 (西安交通大学)腾讯会议室2022年6月17日(星期五) 10:20-11:20
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Canonical metrics on toric manifolds and G-manifoldsKaehler metrics with large symmetry on a toric manifold correspond to a class of convex functions on the whole euclidean space. This allows us to use more special techniques from convex analysis in the study of Kaehler geometry on toric manifolds. In this talk, we will first discuss various approaches in the study of Kaehler-Einstein metrics on toric Fano manifolds. Then we discuss some recent work, in particular on Kaehler-Ricci flow on G-manifolds by the method used for toric manifolds. Some questions/problems are also discussed.朱小华 教授 (北京大学)腾讯会议室2022年6月17日(星期五) 9:10-10:10
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对数凹函数、局部化方法与泛函不等式对数凹(log-concave)这个概念在凸几何与泛函不等式的研究中扮演着重要的角色。报告人将从对数凹测度谈起,结合最优传输理论,介绍随机局部化方法在泛函不等式研究中的应用。韩邦先 教授 (中国科学技术大学)腾讯会议室2022年6月17日(星期五) 08:00-09:00
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On the Euler+Prandtl Expansion for the Navier-Stokes EquationsWe establish the validity of the Euler+Prandtl approximation for solutions of the Navier-Stokes equations in the half plane with Dirichlet boundary conditions, in the vanishing viscosity limit, for initial data which are analytic only near the boundary, and Sobolev smooth away from the boundary. Our proof does not require higher order correctors, and works directly by estimating an L1 -type norm for the vorticity of the error term in the expansion Navier-Stokes−(Euler+Prandtl). An important ingredient in the proof is the propagation of local analyticity for the Euler equation, a result of independent interest.王飞 副教授 (上海交通大学)腾讯会议室2022年6月15日(星期三) 9:00-10:00
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Regularities of solutions to two Minkowski problemsIn this talk, we will study C^{1, 1} regularity for solutions to the degenerate Lp Dual Minkowski problem and the existence of the smooth solution to the Gauss image.腾讯会议号:131-965-267会议链接://meeting.tencent.com/dm/iD9IGmFJEu19 All are ...陈立 副教授 (湖北大学)腾讯会议室2022年5月27日 10:00-11:00
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Asymptotic convergence for a class of anisotropic curvature flowsIn this talk, by using new auxiliary functions, we study a class of contracting flows of closed, star-shaped hypersurfaces in R^n+1 with speed $r^{\frac{\alpha}{\beta}} \sigma_k^{\frac{1}{\beta}}$, where $\sigma_k$ is the $k$-th element...李海中 教授 (清华大学)腾讯会议室2022年5月27日 9:00-10:00
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On minimal surfaces in R^n and spacelike stationary surfaces in R^4_1In this talk, we will first introduce some classical topics concerning the geometry of minimal surfaces in R^n. Then we will discuss the Bernstein type theorems and Gauss-Bonnet type formula for minimal surfaces in R^3 or R^n...王鹏 教授 (福建师范大学)腾讯会议室2022年5月27日(星期五) 8:00-9:00