NOETHER’S CONSERVATION LAWS OF HOLONOMIC NONCONSERVATIVE DYNAMICAL SYSTEMS IN GENERALIZED MECHANICS

In the present paper, three kinds of forms for Noether’s conservation laws of hol-onomic nonconservative dynamical systems in generalized mechanics are given.

Fractional Optical Solitons and Fractional Noether’s Theorem with Ortigueira’s Centered Derivatives

This paper shows that the centered fractional derivatives introduced by Manuel Duarte Ortigueira in 2006 are useful in the description of optical solitons. It is shown that we can construct a fractional extension of the nonlinear Schrödinger (NLS) equation which incorporates Ortigueira’s derivatives and has soliton solutions. It is also shown that this fractional NLS equation has a Lagrangian density and can be derived from a variational principle. Finally, a fractional extension of Noether’s theorem is formulated to determine the conserved quantities associated to the invariances of the action integral under infinitesimal transformations.

Framing Noether’s Theorem

We discuss Noether’s theorem from a new perspective and show that the spatial continuous symmetries of a system are on one hand symmetries of the space and on the other hand are dictated by the system’s potential energy. The Noether’s charges arising from an infinitesimal motion, or a Killing vector field, of the space, are conserved if the Lie derivative of the potential energy by this vector field vanishes. The possible spatial symmetries of a mechanical system are listed according to the potential energy of the external forces.

The Lynx and Hare Data of 200 Years as the Nonlinear Conserving Interaction Based on Noether’s Conservation Laws and Stability

We applied n-variable conserving nonlinear differential equations (n-CNDEs) to the population data of the 10-year cycles of Canadian lynx (1821-2016) and the snowshoe hare (1845-1921). Modeling external effects as perturbations to population dynamics, recovering and restorations from disintegrations (or extinctions), stability and survival strategies are discussed in terms of the conservation law inherent to dynamical interactions among species. The 2-variable conserving nonlinear interaction (2CNIs) is extended to 3, 4, ... n-variable conserving nonlinear interactions (n-CNIs) of species by adjusting minimum unknown parameters. The population cycle of species is a manifestation of conservation laws existing in complicated ecosystems, which is suggested from the CNDE analysis as a standard rhythm of interactions. The ecosystem is a consequence of the long history of nonlinear interactions and evolutions among life-beings and the natural environment, and the population dynamics of an ecosystem are observed as approximate CNIs. Physical analyses of the conserving quantity in nonlinear interactions would help us understand why and how they have developed. The standard rhythm found in nonlinear interactions should be considered as a manifestation of the survival strategy and the survival of the fittest to the balance of biological systems. The CNDEs and nonlinear differential equations with time-dependent coefficients would help find useful physical information on the survival of the fittest and symbiosis in an ecosystem.

Dark Energy from Kaluza-Klein Spacetime and Noether’s Theorem via Lagrangian Multiplier Method

The supposedly missing dark energy of the cosmos is found quantitatively in a direct analysis without involving ordinary energy. The analysis relies on five dimensional Kaluza-Klein spacetime and a Lagrangian constrained by an auxiliary condition. Employing the Lagrangian multiplier method, it is found that this multiplier is equal to the dark energy of the cosmos and is given by where E is energy, m is mass, c is the speed of light, and λ is the Lagrangian multiplier. The result is in full agreement with cosmic measurements which were awarded the 2011 Nobel Prize in Physics as well as with the interpretation that dark energy is the energy of the quantum wave while ordinary energy is the energy of the quantum particle. Consequently dark energy could not be found directly using our current measurement methods because measurement leads to wave collapse leaving only the quantum particle and its ordinary energy intact.

NOETHER’S THEORY OF VACCO DYNAMICS

In this paper, we first study the latent relation between the conservative quantity and the symmetry of nonholonomic dynamical systems without any additional restrictive conditions to its virtual displacement, and then establish Noether's theorem and Noether's inverse theorem of Vacco dynamics. Lastly, we give two examples to illustrate the application of result of this paper.

NOETHER’S THEORY FOR NONHOLONOMIC DYNAMICAL SYSTEMS RELATIVE TO NON-INERTIAL REFERENCE FRAME

The new variational principle of Gauss's form of nonlinear nonholonomic nonpotential system relative to non-inertial reference frame is established by constructing generalized inertial potentials. Naether's theorem and Naether's inverse theorem of the system above is presented and proved. Finally, one example is given to illustrate the application.

GENERALIZED NOETHER’S THEOREM OF NONHOLONOMIC NONPOTENTIAL SYSTEM IN NONINERTIAL REFERENCE FRAMES

The new Lagrangian of the relative motion of mechanical system is constructed, the varialional principles oj Jourdain's form of nonlinear nonlwlonomic nonpotential system in noninertial reference frame are established, the generalized Noether's theorem of the system above is presented and proved, and the conserved quantities of system are studied.

广义Birkhoff系统分数阶最优控制问题的Noether定理

探讨了广义Birkhoff系统分数阶最优控制问题的Noether定理。首先,基于Caputo分数阶导数提出广义Birkhoff系统的分数阶最优控制问题,并运用分数阶变分方法得到了广义Birkhoff系统的分数阶最优控制问题的极值条件。然后,运用分数阶微积分和分数阶变分方法讨论了泛函在无穷小变换群作用下的不变性,分别给出了其时间不变和时间变化情况下的分数阶最优控制问题的Noether定理。最后,应用实例显示方法的有效性。

非保守非完整系统的Herglotz型Noether定理

研究非保守非完整系统的Herglotz型Noether定理及其逆定理.首先,将Herglotz变分原理推广到非保守非完整系统,并基于该原理推导出系统的带乘子型运动微分方程.其次,引入无限小变换,研究Herglotz作用量的不变性,提出并证明非保守非完整系统的Noether定理.再次,研究了对称性逆问题,给出了Noether逆定理.最后,以受非保守力的Appell-Hamel问题为例,介绍Herglotz型Noether定理的应用.

二阶非完整Vacco动力学及其Noether定理

研究非完整约束Vacco动力学及其Noether对称性。建立二阶非完整系统的Vacco型变分原理,导出Vacco动力学方程。利用全变分与等时变分之间的关系,导出复合作用量的全变分公式。通过复合作用量在无限小变换下的不变性,定义Noether对称与准对称变换,给出对称性判据的Noether等式。建立二阶非完整约束Vacco动力学系统的Noether定理。如果约束是一阶非完整的,则定理退化为一阶非完整Vacco动力学的Noether定理。文末给出一个算例以演示定理之应用。

具有混合导数的分数阶约束Hamilton系统的Noether对称性

研究了混合整数阶和Riemann-Liouville分数阶导数下的分数阶奇异系统。建立了分数阶奇异Lagrange方程和分数阶约束Hamilton方程。为了寻找该奇异系统微分方程的解,论文研究了Noether对称性,并得到了相应的守恒量。即,建立了混合整数阶和Riemann-Liouville分数阶导数下的分数阶奇异系统的Noether定理。

基于非标准Lagrange函数的分数阶Lagrange系统的Noether对称性与守恒量

研究基于两类非标准Lagrange函数(指数Lagrange函数和幂律Lagrange函数)的分数阶Lagrange系统的Noether对称性与守恒量.首先,分别导出Caputo分数阶导数下两类非标准Lagrange系统的运动微分方程;其次,根据作用量在无穷小变换下的不变性,给出了分数阶非标准Lagrange系统的Noether对称变换的定义和判据;最后,建立系统的Noether定理并举例说明结果的应用.

Fractional Noether theorem and fractional Lagrange equation of multi-scale mechano-electrophysiological coupling model of neuron membrane

Noether theorem is applied to a variable order fractional multiscale mechano-electrophysiological model of neuron membrane dynamics.The variable orders fractional Lagrange equation of a multiscale mechano-electrophysiological model of neuron membrane dynamics is given.The variable orders fractional Noether symmetry criterion and Noether conserved quantities are given.The forms of variable orders fractional Noether conserved quantities corresponding to Noether symmetry generators solutions of the model under different conditions are discussed in detail,and it is found that the expressions of variable orders fractional Noether conserved quantities are closely dependent on the external nonconservative forces and material parameters of the neuron.

时间尺度上非完整系统的Noether准对称性与守恒量

提出并研究时间尺度上非完整系统的Noether准对称性与守恒量.首先,将时间尺度上非完整系统的运动微分方程化为时间尺度上一般完整系统的Lagrange方程,在Lagrange框架下建立时间尺度上Noether定理,给出时间尺度上Noether守恒量;其次将时间尺度上非完整系统的运动微分方程化为时间尺度上相空间中一般完整系统的Hamilton方程,在Hamilton框架下建立时间尺度上Noether定理,给出时间尺度上Noether守恒量;再次,将时间尺度上非完整系统的运动微分方程化为时间尺度上广义Birkhoff方程,在Birkhoff框架下依据时间尺度上Noether准对称性的定义,建立时间尺度上Noether定理和广义Noether等式,给出时间尺度上Noether守恒量.最后,举例说明结果的应用.

事件空间中单面约束系统的Noether定理

首先提出了事件空间中单面约束系统的D Alembert Lagrange原理 ;其次基于微分变分原理在群的无限小变换下的不变性 ,研究并给出事件空间中单面约束系统的Noether定理及逆定理 ;最后举例说明结果的应用 .

Birkhoff系统的一般Lie对称性和非Noether守恒量

研究Birkhoff系统的一般Lie对称性导致的非Noether守恒量。得到非Noether守恒量的存在定理,举例说明结果的应用。

事件空间中单面非Chetaev型非完整系统的Noether定理

研究事件空间中单面非Chetaev型非完整系统的Noether定理· 首先给出了系统的D’Alem bert_Lagrange原理 ;其次基于该原理在群的无限小变换下的不变性 ,研究了非Chetaev型非完整系统的Noether定理及逆定理 ;

作战微分方程模型的Noether对称性

将一般微分方程组部分正则化 ,利用 Hamilton作用量在无限小变换下的不变性找到系统的守恒量。利用一般理论研究几种作战微分方程模型的

基于Caputo分数阶导数的含时滞的非保守系统动力学的Noether对称性

提出并研究基于Caputo分数阶导数的含时滞的力学系统的Noether对称性与守恒量。建立了含时滞的非保守系统的分数阶运动微分方程;根据系统的含时滞的分数阶Hamilton作用量在无限小群变换下的泛函不变性,给出了含时滞的分数阶Noether对称变换,Noether准对称变换以及Noether广义准对称变换的定义判据;研究了含时滞的分数阶Noether对称性与守恒量之间的联系,并举例说明结果的应用。