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891.
A formula for the distance of a Toeplitz matrix to the subspace of {ei?}‐circulant matrices is presented, and applications of {ei?}‐circulant matrices to preconditioning of linear systems of equations with a Toeplitz matrix are discussed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
892.
R. Bruce Richter 《Discrete Mathematics》2011,(15):1390
Thomassen and Vella (Graph-like continua, augmenting arcs, and Menger’s Theorem, Combinatorica, doi:10.1007/s00493-008-2342-9) have recently introduced the notion of a graph-like space, simultaneously generalizing infinite graphs and many of the compact spaces recently used by Diestel or Richter (and their coauthors) to study cycle spaces and related problems in infinite graphs. This work is a survey to introduce graph-like spaces and shows how many of these works on compact spaces can be generalized to compact graph-like spaces. 相似文献
893.
In this paper we study U-bounds in relation to L1-type coercive inequalities and isoperimetric problems for a class of probability measures on a general metric space (RN,d). We prove the equivalence of an isoperimetric inequality with several other coercive inequalities in this general framework. The usefulness of our approach is illustrated by an application to the setting of H-type groups, and an extension to infinite dimensions. 相似文献
894.
《Communications in Nonlinear Science & Numerical Simulation》2014,19(3):538-553
This article proposes spectral numerical methods to solve the time evolution of convection problems with viscosity strongly dependent on temperature at infinite Prandtl number. Although we verify the proposed techniques solely for viscosities that depend exponentially on temperature, the methods are extensible to other dependence laws. The set-up is a 2D domain with periodic boundary conditions along the horizontal coordinate which introduces a symmetry in the problem. This is the O(2) symmetry, which is particularly well described by spectral methods and motivates the use of these methods in this context. We examine the scope of our techniques by exploring transitions from stationary regimes towards time dependent regimes. At a given aspect ratio, stable stationary solutions become unstable through a Hopf bifurcation, after which the time-dependent regime is solved by the spectral techniques proposed in this article. 相似文献
895.
In this article we study the top of the spectrum of the normalized Laplace operator on infinite graphs. We introduce the dual Cheeger constant and show that it controls the top of the spectrum from above and below in a similar way as the Cheeger constant controls the bottom of the spectrum. Moreover, we show that the dual Cheeger constant at infinity can be used to characterize that the essential spectrum of the normalized Laplace operator shrinks to one point. 相似文献
896.
A probabilistic characterization is given for Schneider?s generalized stable laws. They belong to the larger family of laws which are invariant under length-biasing followed by a random beta scaling. Questions of infinite divisibility and self-decomposability are pursued. Moment determinacy of reciprocal generalized stable laws are investigated. 相似文献
897.
898.
一类特殊的对称的块循环矩阵的特征值 总被引:2,自引:0,他引:2
WangLigong LiXueliang HoedeC 《高校应用数学学报(英文版)》2004,19(1):17-26
In this paper, the spectrum and characteristic polynomial for a special kind of symmetric block circulant matrices are given. 相似文献
899.
讨论三元 r-循环实矩阵 ,给出了三元 r-循环实矩阵的行列式和逆矩阵的实表达式 .从而得到r-循环实矩阵的行列式和逆矩阵的实表达式 相似文献
900.
Ariadna J. Torres-Arenas Qian Dong Guo-Hua Sun Shi-Hai Dong 《Physics letters. A》2018,382(26):1752-1759
We show how the product of the radial position and momentum uncertainties can be obtained analytically for the infinite circular well potential. Some interesting features are found. First, the uncertainty Δr increases with the radius R and the quantum number n, the n-th root of the Bessel function. The variation of the Δr is almost independent of the quantum number n for and it will arrive to a constant for a large n, say . Second, we find that the relative dispersion is independent of the radius R. Moreover, the relative dispersion increases with the quantum number n but decreases with the azimuthal quantum number m. Third, the momentum uncertainty Δp decreases with the radius R and increases with the quantum numbers and n. Fourth, the product of the position-momentum uncertainty relations is independent of the radius R and increases with the quantum numbers m and n. Finally, we present the analytical expression for the Fisher entropy. Notice that the Fisher entropy decreases with the radius R and it increases with the quantum numbers and n. Also, we find that the Cramer–Rao uncertainty relation is satisfied and it increases with the quantum numbers and n, too. 相似文献