检索结果-南通市图书馆

Extremal functions for the Moser-Trudinger inequalities on compact Riemannian manifolds

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Mathematics 2005年第5期48卷 618-648页

作者： LI Yuxiang department of mathematical sciences, tsinghua university, beijing 100084, china department of mathematical sciences Tsinghua University Beijing China

Let (M, g) be a compact Riemannian manifold without boundary, and (N, g) a compact Riemannian manifold with boundary. We will prove in this paper that the ∫MudVg=o,sup∫M|(△↓)u|ndVg=1∫Meαn|u|n/n-1dVg,∫M(|(△↓)|n+|u|n)dVg=1∫Meαn|u|n/n-1dVg,and u|(e)N=0,∫Msup|(△↓)u|dVgN=1∫Neαn|u|n/n-1dVgn can be attained. Our proof uses the blow-up analysis.

关键词： Moser-Trudinger inequality extremal function n-Lapalace Green function.

QUASI-STATIONARY DISTRIBUTIONS FOR THE RADIAL ORNSTEIN-UHLENBECK PROCESSES

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2008年第3期28卷 513-522页

作者：叶俊 department of mathematical sciences Tsinghua University

The purpose of this article is to obtain the quasi-stationary distributions of the δ（δ 〈 2）-dimensional radial Ornstein-Uhlenbeck process with parameter -λ by using the methods of Martinez and San Martin （2001）. It is described that the law of this process conditioned on first hitting 0 is just the probability measure induced by a （4 - δ）- dimensional radial Ornstein-Uhlenbeck process with parameter -λ. Moreover, it is shown that the law of the conditioned process associated with the left eigenfunction of the process conditioned on first hitting 0 is induced by a one-parameter diffusion.

关键词： Radial Ornstein-Uhlenbeck process quasi-stationary distribution quasiinvariant

Local Gromov-Witten invariants of canonical line bundles of toric surfaces

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2010年第6期53卷 1571-1582页

作者： YANG Fei & ZHOU Jian department of mathematical sciences,tsinghua university,beijing 100084,china department of mathematical sciences Tsinghua University Beijing China

We define and compute by localizating the local equivariant Gromov-Witten invariants of the canonical line bundles of toric surfaces,not necessarily Fano.

关键词： local Gromov-Witten invariants localization partition function geometric engineering

Classification of hypersurfaces with parallel Mobius second fundamental form in S^(n+1)

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2004年第3期47卷 417-430页

作者： HU Zejun LI Haizhong department of Mathematics, Zhengzhou university Zhengzhou 450052, china department of mathematical sciences, tsinghua university, beijing 100084, china department of Mathematics Zhengzhou University Zhengzhou China department of mathematical sciences Tsinghua University Beijing China

Let Mn(n≥2) be an immersed umbilic-free hypersurface in the(n+1)-dimensional unit sphere Sn+1. Then Mn is associated witha so-called M(o)bius metric g, and a M(o)bius second fundamental form Bwhich are invariants of Mn under the M(o)bius transformation groupof Sn+*** this paper, we classify all umbilic-free hypersurfaces withparallel M(o)bius second fundamental form.

关键词： parallel Mobius second fundamental form,hypersurface, Mobius metric, Mobius equivalence.

CONVEXITY AND SYMMETRY OF TRANSLATING SOLITONS IN MEAN CURVATURE FLOWS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2005年第3期26卷 413-422页

作者： JIANHUAIYU LIUQINGHUA CHENXIUQING departmentofmathematicalsciences TsinghuaUniversityBeijing100084China Projectsupportedbythe973ProjectoftheMinistryofScienceandTechnologyofchinaandtheTrans-CenturyTrainingProgrammeFoundationfortheTalentsbytheMinistryofEducationofchina

This paper proves that any rotationally symmetric translating soliton of mean curvature flow in Rs is strictly convex if it is not a plane and it intersects its symmetric axis at one point. The authors also study the ... 详细信息

关键词：凸空间孤波平均曲率流旋转对称表面光滑流形

Unramified extensions of quadratic fields

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2008年第3期18卷 323-324页

作者： Wei Li, Dong Yang, Xianke Zhang department of mathematical sciences, tsinghua university, beijing 100084, china department of mathematical sciences Tsinghua University Beijing 100084 China

Let K be a global quadratic field, then every unramified abelian extension of Kis proved to be absolutely Galois when Kis a number field or under some natural conditions when Kis a function field. The absolute Galois ... 详细信息

关键词： Global quadratic fields Unramified extensions

The Double Ringel-Hall Algebras of Valued Quivers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2006年第6期27卷 701-722页

作者： Yanxin WANG Jie XIAO department of mathematical sciences Tsinghua University Beijing 100084 China College of mathematical Science Tianjin Normal University Tianjin 300384 China

这篇论文被奉献给双 Ringel-Hallalgebra D 的结构的学习(为无限的维的世袭代数学Λ的Λ)，它被给由一珍视发抖在一块有限的地上的Γ ，并且另外到 D 的关系的学习(与代表一起的Λ)模块珍视发抖Γ。

关键词： Ringel-Hall代数广义Kac-Moody代数 Drinfeld双精度近世代数

Twistor bundle theory and its application

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2004年第4期47卷 605-616页

作者： PENG Chia-Kuei & tanG Zizhoudepartment of Mathematics, Graduate School of Chinese Academy of sciences, beijing 100039, china department of mathematical sciences, tsinghua university, beijing 100084, china department of Mathematics Graduate School of Chinese Academy of Sciences Beijing China department of mathematical sciences Tsinghua University Beijing China

Over an oriented even dimensional Riemannian manifold (M2m, ds2), in terms of the Levi-Civita connection form Ω and the canonical form Θ on the bundle of positive or→ J+(M, ds2) → M. The integrability on an almost complex structure J compatible with the metric and the orientation, is shown to be equivalent to the fact that the corresponding cross section of the twistor bundle is holomorphic with respect to J and the canonical almost complex structure J1 on J+(M, ds2), by using moving frame theory. Moreover, for various metrics and a fixed orientation on M, a canonical bundle isomorphism is established. As a consequence, we generalize a celebrated theorem of LeBrun.

关键词： almost complex structure, integrability, twistor bundle.

RELAXATION TIME LIMITS PROBLEM FOR HYDRODYNAMIC MODELS IN SEMICONDUCTOR SCIENCE

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2007年第2期27卷 437-448页

作者：黎勇 College of Applied Science beijing university of Technology

In this article, two relaxation time limits, namely, the momentum relaxation time limit and the energy relaxation time limit are considered. By the compactness argument, it is obtained that the smooth solutions of the multidimensional nonisentropic Euler-Poisson problem converge to the solutions of an energy transport model or a drift diffusion model, respectively, with respect to different time scales.

关键词： Hydrodynamic models nonisentropic Euler-Poisson momentum relaxation time limit energy relaxation time limit