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设M为一带边界M的紧致Riemann流形,本文考虑M上的下述混合边值条件的特征值问题 (△u+v_1u=0, u/n+αu|M=0,)其中n为M的外法向单位向量,α为一正常数。 相似文献
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《数学的实践与认识》2015,(9)
研究了一类系数中带有幂函数和指数函数的高阶对称微分算子,给出常系数下此类微分算子的本质谱的分布,并得到对其系数加满足一定条件的相关摄动后本质谱不改变的结论. 相似文献
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设M2m+1(K)是Zn+1维常ψ一截面曲率K的紧致Sasaki流形,本文证明了与M2m+1(K)等谱的上同调Einstein的紧致Sasaki流形必有常ψ-截面曲率K. 相似文献
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本文探讨加权Bergman空间Ap(φ)上Toeplitz算子,刻画了L∞(D)的使得符号在其中的Toeplitz算子的半换位子是紧算子的最大的自伴子代数Q,并计算了符号在Q中的Toeplitz算子的本质谱和Fredholm指标. 相似文献
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局部对称共形平坦黎曼流形中带有平坦法丛的子流形 总被引:1,自引:0,他引:1
设M~(n p)是n p维共形平坦黎曼流形,且它的黎曼张量R_(tjkl)之共变导微▽R_(tjkl)=0,则称M~(n p)为局部对称共形平坦黎曼流形。 本文证得:若V~n(n≥2)是局部对称共形平坦黎曼流形M~(n p)的n维紧致无边子流形,它具有平坦法丛,若V~n在任一点上的截面曲率均大于T_c-t_c/2(n p-2),这里T_c、t_c分别是M~(n p)的Ricci曲率在该点的上、下确界,则V~n一定是M~(n p)的n 1维全测地子流形M~(n 1)之超曲面。 相似文献
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H.Yanamoto 在[2],[3]中有一猜想:对于任何黎曼流形 M~n,共形 Killingp-形式 u 的对偶*u 还是共形 Killing 形式。当 n=3时,这一结论的正确性由[3]给出.本文证明了对任何高维流形,结论都正确. 相似文献
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主要研究了局部对称的黎曼流形中的定向紧致无边极小子流形的内蕴刚性问题,利用一个矩阵不等式,得到了这类子流形的一个刚性定理.所得结果部分改进了已有的一个结论. 相似文献
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本文讨论了积流形的P-形式上Laplace算子谱的唯一性问题,在紧Kachler流形乘积和紧Sasaki流形乘积的两类积流形中,CPn×CPn和S2n+1(1)×S2n+1(1)是P-形式上Laplacce算子谱特征。 相似文献
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Mary R. Sandoval 《偏微分方程通讯》2013,38(10):1818-1846
Given a compact boundaryless Riemannian manifold upon which a compact Lie group G acts by isometries, recall that the G-invariant Laplacian is the restriction of the ordinary Laplacian on functions to the space of functions which are constant along the orbits of the action. By considering the wave trace of the invariant Laplacian and the connection between G manifolds and Riemannian foliations, invariants of the spectrum of the G-invariant Laplacian can be computed. These invariants include the lengths of certain geodesic arcs which are orthogonal to the principal orbits and contained in the open dense set of principal orbits are associated to the singularities of the wave trace of the G-invariant spectrum. If the action admits finite orbits, then the invariants also include the lengths of certain geodesics arcs connecting the finite orbit to itself. Under additional hypotheses, we obtain partial wave traces. As an application, a partial trace formula for Riemannian foliations with bundle-like metrics is also presented, as well as several special cases where better results are available. 相似文献
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We study average growth of the spectral function of the Laplacian on a Riemannian manifold. Two types of averaging are considered: with respect to the spectral parameter and with respect to a point on a manifold. We obtain as well related estimates of the growth of the pointwise ζ-function along vertical lines in the complex plane. Some examples and open problems regarding almost periodic properties of the spectral function are also discussed. 相似文献
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本文讨论了Riemann流形上由Hodge-deRham算子△生成的热半群{e^t△}t≥0的渐近性质和L^p压缩性。 相似文献
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Let M be a compact smooth Riemannian manifold with smooth boundary. We establish the existence of an asymptotic series for the heat content of M with a perfect conducting boundary and show that the coefficients in the series are non-local invariants which are recursively determined by the coefficients for the series with corresponding zero Dirichlet boundary condition. 相似文献
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本文利用Nakagawa和Takagi的计算散度的方法,求出局部对称空间中具有平行平均曲率向量的黎曼叶状结构${\cal F}$上向量场的散度,并证明了其上的整体Pinching定理. 相似文献
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In this paper,we study gradient estimates for the nonlinear heat equation ut-△u =au log u,on compact Riemannian manifold with or without boundary.We get a Hamilton type gradient estimate for the positi... 相似文献
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极小子流形上Laplace算子的谱 总被引:2,自引:0,他引:2
本文讨论了Sn+p(1)(或CPn+1)中极小子流形上Laplace算子的谱,证明了Sn+p(1)中全测地极小子流形(或CPn+1中Kachler超曲面)是由作用在q-形式上的Laplace算子的谱唯一确定. 相似文献