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21.
22.
Zhenxin Liu 《数学研究通讯:英文版》2023,39(3):476-500
The limit distribution for homogeneous Markov processes is studied extensively and well understood, but it is not the case for inhomogeneous
Markov processes. In this paper, we review some recent results on inhomogeneous Markov processes generated by non-autonomous stochastic (partial)
differential equations (SDE in short). Under some suitable conditions, we show
that the distribution of recurrent solutions of SDEs constitutes the limit distribution of the corresponding inhomogeneous Markov processes. 相似文献
23.
邹黎敏 《浙江大学学报(理学版)》2013,40(1):27-28
最近,对于任何的酉不变范数,KITTANEH得到了Heinz不等式的一个改进. 在这篇注记中,得到了KITTANEH结果的一个改进. 相似文献
24.
In this paper, a detailed Lie symmetry analysis of the(2+1)-dimensional coupled nonlinear extension of the reaction-diffusion equation is presented. The general finite transformation group is derived via a simple direct method,which is equivalent to Lie point symmetry group actually. Similarity reduction and some exact solutions of the original equation are obtained based on the optimal system of one-dimensional subalgebras. In addition, conservation laws are constructed by employing the new conservation theorem. 相似文献
25.
Starting from the continuity, temperature, and motion equations
of the trapped electron fluid in general tokamak magnetic field
with positive or reversed shear and the definition of Lagrangian
invariant, dL/dt≡(\partialt+
u•▽)L=0, where
u is convective velocity, the trapped electron dynamics is considered in the following two assumptions: (i)
the turbulence is low frequency electrostatic, and (ii) L is a functional only of the density n, temperature T, and magnetic field B, and the effect of perturbation
potential φ is included in the convective velocity u, i.e.,
u is a functional of n, T, B, and φ. The Lagrangian invariant hidden in the trapped electron dynamics is strictly found:
L=ln[(n/B)c1(T/B2/3)c2], where
c1 and c2 are dimensionless changeable parameters and
c1∝c2. From this Lagrangian invariant
the turbulent particle and electron
thermal transport scaling laws are derived:
〈n>ψq(ψ)=const. and
〈T3/2>ψq(ψ)=const.,
which, in the limit of large aspect ratio, reduce to
n(r)q(r)=const.
and T3/2(r)q(r)=const., respectively. The latter two scaling
laws are compared with existent experimental results, being in good
agreement. 相似文献
26.
A simple method to measure the complex degree of spatial coherence of a partially coherent quasi-monochromatic light field is presented. The Fourier spectrum of the far-field interferogram generated by a mask with multiple apertures (small circular holes) is analyzed in terms of classes of aperture pairs. A class of aperture pairs is defined as the set of aperture pairs with the same separation vector. The height of the peaks in the magnitude spectrum determines the modulus of the complex degree of spatial coherence and the corresponding value in the phase spectrum determines the phase of the complex degree of spatial coherence. The method is illustrated with experimental results. 相似文献
27.
28.
We determine curvature properties of pseudosymmetric type of certain warped product manifolds, and in particular of generalized Robertson–Walker spacetimes, with Einsteinian or quasi-Einsteinian fibre. 相似文献
29.
We define nontempered (exponential growth) function spaces on the Lie group ax+b which are stable under some left-invariant (convergent) star product. The techniques used to achieved the latter come from symmetric spaces geometry and star representation theory. 相似文献
30.
李中林 《浙江大学学报(理学版)》1989,16(3):237-244
本文讨论局部对称共形平坦Riemann流形N中的紧致H稳定子流形M,若M具于平行平均曲率向量场,则对M的截面曲率或Ricci曲率加上适当的限制条件后,我们证明了M是N中某全脐点子流形N~(N+1)的全脐点超曲面。 相似文献