与相对论Boltzmann方程中的输运算子有关的紧性

该文给出了一个与相对论Boltzmann方程中的输运算子有关的紧性的结果，它是一个类似于DiPerna和Lions在非相对论情况下给出的紧性的结果的推广，在研究相对论Boltzmann方程中起着很重要的作用．     

周期单元中相对论Boltzmann方程初值问题整体解的存在性

本文证明了周期单元中带有某些硬相互作用的相对论Ｂｏｌｔｚｍａｎｎ方程初值问题在初值满足质量、能量和熵有限的条件下具有一个整体温和解．     

Boltzmann方程的两个解的平均作为二粒子Boltzmann方程系的解

在这篇文章,由Boltzmann方程的两个解构造出二粒子Boltzmann方程系的一类解。利用这个结果,求出了二粒子Boltzmann方程系的平衡解及宏观运动方程组。     

相对论裸粒子Green函数和碰撞积分

从相对论非平衡态统计系综理论出发,利用Bogoliubov假设和极化近似,用裸粒子Green函数方法求解相对论两体关联方程,导出用裸粒子Green函数表示的相对论动力方程碰撞积分的一般公式,导出适用于相对论等离子体的的“广义Boltzmann方程”.     

一类Boltzmann方程的临界解

以多种应用为背景的Boltzmann方程,其临界解的讨论已有许多结果,例如,具齐次边界条件的柱模型,具广义反射边界条件的球模型,对于平板模型,有广义反射边界条件和积分边界条件的讨论,但都局限于有限板的情形。对于无限介质的平板模型,G.C.Pomraning讨论了如下特殊的临界间题:     

关于弱非线性、弱涨落的Boltzmann方程链的经典解的存在性问题

本文按照Grad~([6])指出的方法具体地证明了弱非线性、弱涨落的Boltzmann方程链的经典解的存在性.     

一类耗散Boltzmann方程的渐近稳定性

探讨了满足质量、动量守恒,能量耗散的空间齐次硬位势Boltzmann方程,对方程作PseudoMaxwellian逼近处理,证明了方程的解按概率距离指数收敛到稳定态解.     

空间齐次推广的耗散碰撞Bootzmann方程的Cauchy问题(英文)

关于一类空间齐次推广的耗散碰撞Boltzmann方程Cauchy问题 ,对于一般的初始条件得到了正古典解的存在唯一性 .     

二粒子Boltzmann方程组的奇异扰动解法

讨论了二粒子Boltzmann方程组的边界层解.为此我们先对未知变量进行了Fourier变换,然后运用前人的方法对变换后的函数进行展开.通过对未知变量做一些特殊的函数展开,得到了二粒子Boltzmann方程组的正规解和边界层解,并得到了边界层解的初级和高级近似.     

二粒子Boltzmann方程组的奇异扰动解法:初始层解

本文讨论了二粒子Boltzmann方程组的初始层解.为此先对未知变量进行了Fourier变换,然后运用奇异扰动解法得到了二粒子Boltzmann方程组的正规解和初始层解以及其初始层解的初级和高级近似,并且得到了初始层解和正规解的连接.     

Estimation of the measure of the image of the ball

Under study is the class of ring Q-homeomorphisms with respect to the p-module. We establish a criterion for a function to belong to the class and solve a problem that stems from M. A. Lavrentiev [1] on the estimation of the measure of the image of the ball under these mappings. We also address the asymptotic behavior of these mappings at a point.     

On the distributions of the ratios of the extreme roots to the trace of the Wishart matrix

In this paper, the authors cosider the derivation of the exact distributions of the ratios of the extreme roots to the trace of the Wishart matrix. Also, exact percentage points of these distributions are given and their applications are discussed.     

On the rational approximation of the sum of the reciprocals of the Fermat numbers

Let $\mathcal{G}(z):=\sum_{n\geqslant0} z^{2^{n}}(1-z^{2^{n}})^{-1}$ denote the generating function of the ruler function, and $\mathcal {F}(z):=\sum_{n\geqslant} z^{2^{n}}(1+z^{2^{n}})^{-1}$ ; note that the special value $\mathcal{F}(1/2)$ is the sum of the reciprocals of the Fermat numbers $F_{n}:=2^{2^{n}}+1$ . The functions $\mathcal{F}(z)$ and $\mathcal{G}(z)$ as well as their special values have been studied by Mahler, Golomb, Schwarz, and Duverney; it is known that the numbers $\mathcal {F}(\alpha)$ and $\mathcal{G}(\alpha)$ are transcendental for all algebraic numbers α which satisfy 0<α<1. For a sequence u, denote the Hankel matrix $H_{n}^{p}(\mathbf {u}):=(u({p+i+j-2}))_{1\leqslant i,j\leqslant n}$ . Let α be a real number. The irrationality exponent μ(α) is defined as the supremum of the set of real numbers μ such that the inequality |α?p/q|<q ^?μ has infinitely many solutions (p,q)∈?×?. In this paper, we first prove that the determinants of $H_{n}^{1}(\mathbf {g})$ and $H_{n}^{1}(\mathbf{f})$ are nonzero for every n?1. We then use this result to prove that for b?2 the irrationality exponents $\mu(\mathcal{F}(1/b))$ and $\mu(\mathcal{G}(1/b))$ are equal to 2; in particular, the irrationality exponent of the sum of the reciprocals of the Fermat numbers is 2.     

Refinement of the asymptotics of the power of the quantile test

One investigates the asymptotic properties of the quantile test, similar to the properties of the Pearson's chi-square test of fit.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 153, pp. 5–15, 1986.The author is grateful to D. M. Chibisov for useful remarks.     

On the approximation of positive operators and the behaviour of the spectra of the approximants

LetT be a positive linear operator on the Banach latticeE and let (S _n ) be a sequence of bounded linear operators onE which converge strongly toT. Our main results are concerned with the question under which additional assumptions onS _n andT the peripheral spectra (S _n ) ofS _n converge to the peripheral spectrum (T) ofT. We are able to treat even the more general case of discretely convergent sequences of operators.