Newton—Riemann时空中的动力学（Ⅳ）

讨论了Newton-Riemann时空中的Lagrange力学及其与N－R时空中的Newton力学及Hamilton力学的关系。     

光滑流形上非退化L—扩散过程的表示

§1 引言在微分流形上建立扩散过程起源于Bochner构造球面上Brown运动的思想。考虑平面上的二维Brown运动,把一球面在该平面上沿着Brown运动的轨道做无滑动的“滚动”,则Brown运动的轨道在球面上的轨迹便确定了一个随机曲线,它定义了球面上的     

Kaehler流形的Sasaki子流形

Kaehler流形是偶维微分流形,奇维微分流形中,与之媲美的是Sasaki流形。它是正规、切触度量流形。关于Sasaki流形,有判别定理(见[1]中P_(272)定理5.1) 定理A 殆切触度量流形M是Sasaki流形的充要条件为 (xφ)Y=g(X,Y)ξ-g(Y,ξ)X。 (1) 我们知道,Kaehler流形的Sasaki实超曲面是Sasaki流形,其维数也是奇数。Bejancu成功地对Kaehler流形的反全纯子流形引入Sasaki结构,定义了Sasaki反全纯子流形,其维     

关于Kahler流形上的Newton力学

本文讨论Ｋａｈｌｅｒ流形上的Ｎｅｗｔｏｎ力学．在此给出Ｎｅｗｔｏｎ定律、动能定律、动量定律、虚位移原理、Ｄ＇Ａｌｅｍｂｅｒｔ－Ｌａｇｒａｎｇｅ原理、运动方程及“普遍运动方程”等的复的数学形式．     

Newtonian-Riemannian时空中的动力学(Ⅰ)

根据现代微分几何的理论,力学原理及现代微积分把Newtonian-Galilean时空中的动力学推广到Newtonian-Riemannian时空中,建立N-R时空中的动力学,分几个部分,(Ⅰ)是其中之一,余后续。     

Ne wtonian-Rie mannian时空中的动力学(Ⅰ)

根据现代微分几何的理论 ,力学原理及现代微积分把Newtonian_Galilean时空中的动力学推广到Newtonian_Riemannian时空中 ,建立N_R时空中的动力学 ,分几个部分 ,(Ⅰ )是其中之一 ,余后续·     

不变流形方法与非线性控制系统的能控制性

在Kovalev方法基础上运用不变流形研究非线性系统的能控制性问题,得出了一类仿射非线性系统能控的必要条件,讨论了必要条件的实现问题,研究了带有两个陀螺的刚体运动,证明了它满足能控性的必要条件.     

一类对称性破缺的刚-弹耦合系统的运动稳定性

研究了一类对称性破缺的刚-弹耦合系统的Poisson结构和Casimir函数,它们在定常运动的稳定性研究中起重要作用。作为具体实例,给出了重力作用下定点转动的刚-弹耦合系统的Casimir函数的具体形式,最后还给出了圆周轨道上的刚-弹耦合系统的一类定常运动的稳定性充分条件。     

关于流形上鞅的内向爆发

在本文中,我们构造了一个２维完备黎曼流形;其上的布朗运动是非内向爆发的,且存在一个对应于负Ｌｅｖｉ－Ｃｉｖｉｔａ联络的内向爆发鞅。此外,我们也考虑了布朗运动的非内向爆发。     

Newton—Riemann时空中的动力学（Ⅲ）

讨论了Newton-Riemann时空中的动力学－－Hamilton力学及其在流体力学中的应用。     

流体动力学的客观性要求

从流体动力学的客观性要求导出了新的流动理论.流动运动的不均匀性产生粘性力,不同观察者的选取会影响这种不均匀分布特征.将粘性力看作一种与观察者的选取无关的客观存在时,粘性力和动量方程在局域旋转变换下的形式不变性要求引入一种新的动力学场——涡旋场,通过构造流体系统的拉朗日密度并利用能量变分方法得到了所有场量的动力学方程.     

双曲型Lagrangian函数*

双曲复数与Minkowski几何相对应,由四维时空间隔不变量和双曲型Lorentz变换可导出双曲型Lagrangian方程和Hamilton-Jacobi方程.     

Cross section for capture of a particle by a spherically symmetric body and different types of finite motion in the relativistic theory of gravitation

Conclusions It is clear that all properties of the metric (1) that can be formulated in the language of its invariants are identical when these properties are considered in general relativity and in the RTG. For example, the expressions for the cross section for capture of particles by a black hole in general relativity and a sufficiently compact body in the RTG are identical. Similarly, when we consider finite motion of particles in the RTG and in general relativity there are analogous sets of different types of motion of the particles (there is only the characteristic difference in the coordinate r characterized by the relation (6)).We note that circular orbits in the gravitational field of a spherically symmetric body were considered in the framework of the RTG in [3], and it was found that these orbits exist for r>2 and are Lyapunov stable for r>5. A relation characterizing the Thomas precession identical to the corresponding expression obtained in general relativity was also obtained in [3]. Thus, differences between general relativity and the RTG can appear only in properties that are not formulated in the language of the invariants of the metric (1). Therefore, if, for example, we consider the problem of the scattering of a particle by a spherically symmetric compact body in the framework of the RTG and general relativity, then we cannot find a difference between the theories of gravitation, since the expressions for the capture cross sections are the same.Institute of Theretical and Experimental Physics. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 85, No. 1, pp. 150–154, October, 1990.     

Special relativity and theory of gravity via maximum symmetry and localization

Like Euclid,Riemann and Lobachevski geometries are on an almost equal footing,based on the principle of relativity of maximum symmetry proposed by Professor Lu Qikeng and the postulate on invariant universal constants c and R,the de Sitter/anti-de Sitter(dS/AdS)special relativity on dS/AdS-space with radius R can be set up on an almost equal footing with Einstein's special relativity on the Minkowski-space in the case of R→∞. Thus the dS-space is coin-like:a law of inertia in Beltrami atlas with Beltrami time simultaneity for the principle of relativity on one side,and the proper-time simultaneity and a Robertson-Walker-like dS-space with entropy and an accelerated expanding S~3 fitting the cosmological principle on another side. If our universe is asymptotic to the Robertson-Walker-like dS-space of R(?)(3/Λ)~(1/2),it should be slightly closed in O(A)with entropy bound S(?)3πc~3k_B/ΛGh.Contrarily,via its asymptotic behavior, it can fix on Beltrami inertial frames without‘an argument in a circle’and acts as the origin of inertia. There is a triality of conformal extensions of three kinds of special relativity and their null physics on the projective boundary of a 5-d AdS-space,a null cone modulo projective equivalence[N](?)_p(AdS~5). Thus there should be a dS-space on the boundary of S~5×AdS~5 as a vacuum of supergravity. In the light of Einstein's‘Galilean regions’,gravity should be based on the localized principle of relativity of full maximum symmetry with a gauge-like dynamics.Thus,this may lead to the theory of gravity of corresponding local symmetry.A simple model of dS-gravity characterized by a dimensionless constant g(?)(AGh/3c~3)~(1/2)～10~(-61)shows the features on umbilical manifolds of local dS-invariance. Some gravitational effects out of general relativity may play a role as dark matter. The dark universe and its asymptotic behavior may already indicate that the dS special relativity and dS-gravity be the foundation of large scale physics.     

El Naschie’s ε space–time, hydrodynamic model of scale relativity theory and some applications

A generalization of the Nottale’s scale relativity theory is elaborated: the generalized Schrödinger equation results as an irrotational movement of Navier–Stokes type fluids having an imaginary viscosity coefficient. Then ψ simultaneously becomes wave-function and speed potential. In the hydrodynamic formulation of scale relativity theory, some implications in the gravitational morphogenesis of structures are analyzed: planetary motion quantizations, Saturn’s rings motion quantizations, redshift quantization in binary galaxies, global redshift quantization etc. The correspondence with El Naschie’s ε^(∞) space–time implies a special type of superconductivity (El Naschie’s superconductivity) and Cantorian-fractal sequences in the quantification of the Universe.     

S-curvature of Doubly Warped Product of Finsler Manifolds

Doubly warped product of Finsler manifolds is useful in theoretical physics, particularly in general relativity. In this paper, we study doubly warped product of Finsler manifolds with isotropic mean Berwald curvature or weak isotropic S-curvature.     

Shell dynamics in the presence of a central body

We construct an idealized spherically symmetric relativistic model of an exploding object in the framework of the theory of surface layers in general relativity and match a Vaidya solution for a radially radiating star to another Vaidya solution through a thin spherical shell. We reduce the equations of motion and the radiation density of the Vaidya solution given by the matching conditions to a first-order system and analyze the general characteristics of the motion. We use a post-Newtonian approximation to find the equation of motion of a spherically symmetric radiating shell moving in a central gravitational potential.     

Relativistic diffusions and Schwarzschild geometry

The purpose of this article is to introduce and study a relativistic motion whose acceleration, in proper time, is given by a white noise. We deal with general relativity and consider more closely the problem of the asymptotic behavior of paths in the Schwarzschild geometry example. © 2006 Wiley Periodicals, Inc.