共查询到17条相似文献,搜索用时 140 毫秒
1.
研究相空间中离散力学系统对称性的摄动与绝热不变量.列出相空间中未受扰离散力学系统的特殊Lie对称性导致的Hojman型精确不变量.基于相空间中力学系统的高阶绝热不变量的定义,研究在小扰动作用下系统Lie对称性的摄动,得到了相空间中离散力学系统的一类新的绝热不变量——Hojman型绝热不变量.举例说明结果的应用.
关键词:
相空间
Lie对称性
摄动
绝热不变量 相似文献
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研究事件空间中完整力学系统Lie对称性的摄动与绝热不变量.基于力学系统的高阶绝热不变量的概念,研究在小扰动作用下系统Lie对称性的摄动,得到了事件空间中完整力学系统的一类Hojman形式的高阶绝热不变量,给出了绝热不变量存在的条件及形式.并举例说明结果的应用.
关键词:
事件空间
对称性
摄动
绝热不变量 相似文献
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基于El-Nabulsi动力学模型,研究了小扰动作用下Birkhoff系统Noether对称性的摄动与绝热不变量问题.首先,将El-Nabulsi提出的在分数阶微积分框架下基于Riemann-Liouville分数阶积分的非保守系统动力学模型拓展到Birkhoff系统,建立El-Nabulsi-Birkhoff方程;其次,基于在无限小变换下El-Nabulsi-Pfaff作用量的不变性,给出Noether准对称性的定义和判据,得到了Noether对称性导致的精确不变量;再次,引入力学系统的绝热不变量概念,研究El-Nabulsi动力学模型下受小扰动作用的Birkhoff系统Noether对称性的摄动与绝热不变量之间的关系,得到了对称性摄动导致的绝热不变量的条件及其形式.作为特例,给出了El-Nabulsi动力学模型下相空间中非保守系统和经典Birkhoff系统的Noether对称性的摄动与绝热不变量.以著名的Hojman-Urrutia问题为例,研究其在El-Nabulsi动力学模型下的Noether对称性,得到了相应的精确不变量和绝热不变量. 相似文献
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研究小干扰力作用下约束哈密顿系统对称性的摄动问题.建立了非保守约束哈密顿系统的正则方程,在增广相空间中研究了系统的对称性与精确不变量.基于力学系统的高阶绝热不变量的概念,给出了系统的各阶绝热不变量的形式及存在条件,并建立了绝热不变量与对称变换之间的对应关系
关键词:
约束哈密顿系统
对称性
摄动
不变量 相似文献
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研究了Lagrange系统的Lie对称性摄动与新型的非Noether绝热不变量. 列出了未受扰Lagrange系统的Lie对称性导致的Lutzky型精确不变量;基于力学系统的高阶绝热不变量的定义,研究在小扰动作用下Lagrange系统Lie对称性的摄动,得到了系统的一类Lutzky形式的绝热不变量.举例说明方法和结果的应用. 相似文献
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Perturbation to symmetries and Hojman adiabatic invariant for nonholonomic controllable mechanical systems with non-Chetaev type constraints 下载免费PDF全文
This paper studies the perturbation to symmetries and adiabatic
invariant for nonholonomic controllable mechanical systems with
non-Chetaev type constraints. It gives the exact invariants
introduced by the Lie symmetries of the nonholonomic controllable
mechanical system with non-Chetaev type constraints without
perturbation. Based on the definition of high-order adiabatic
invariants of mechanical system, the perturbation of Lie symmetries
for nonholonomic controllable mechanical system with non-Chetaev type
constraints with the action of small disturbances is investigated,
and a new type of adiabatic invariant of system are obtained. In the
end of this paper, an example is given to illustrate the application
of the results. 相似文献
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CHEN Xiang-Wei ZHAO Yong-Hong LI Yan-Min 《理论物理通讯》2005,44(11)
Based on the theory of Lie symmetries and conserved quantities, the exact invariants and adiabatic invariants of nonholonomic system in terms of quasi-coordinates are studied. The perturbation to symmetries for the nonholonomic system in terms of quasi-coordinates under small excitation is discussed. The concept of high-order adiabatic invariant is presented, and the forms of exact invariants and adiabatic invariants as well as the conditions for their existence are given. Then the corresponding inverse problem is studied. 相似文献
13.
CHEN Xiang-Wei ZHAO Yong-Hong LI Yan-Min 《理论物理通讯》2005,44(5):773-778
Based on the theory of Lie symmetries and conserved quantities, the exact invariants and adiabatic invariants of nonholonomic system in terms of quasi-coordinates are studied. The perturbation to symmetries for the nonholonomic system in terms of quasi-coordinates under small excitation is discussed. The concept of high-order adiabatic invariant is presented, and the forms of exact invariants and adiabatic invariants as well as the conditions for their existence are given. Then the corresponding inverse problem is studied. 相似文献
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The exact invariants and the adiabatic invariants of Raitzin's canonical equations of motion for the nonholonomic system of non-Chetaev's type are studied. The relations between the invariants and the symmetries of the system are established. Based on the concept of higher order adiabatic invariant of mechanical system with the action of a small perturbation, the form of the exact invariants and adiabatic invariants and
the conditions for their existence are proved. Finally, the inverse problem
of the perturbation to symmetries of the system is studied and an example is
also given to illustrate the application of the results. 相似文献
15.
Perturbation of Symmetries and Hojman Adiabatic Invariants for Mechanical Systems with Unilateral Holonomic Constraints 总被引:1,自引:0,他引:1
ZHANG Yi FAN Cun-Xin 《理论物理通讯》2007,47(4):607-610
The perturbation of symmetries and adiabatic invariants for mechanical systems with unilateral holonomic constraints are studied. The exact invariant in the form of Hojman led by special Lie symmetries for an undisturbed system with unilateral constraints is given. Based on the concept of high-order adiabatic invariant of mechanical systems, the perturbation of Lie symmetries for the system under the action of small disturbance is investigated, and a new adiabatic invariant for the system with unilateral holonomic constraints is obtained, which can be called Hojman adiabatic invariant. In the end of the paper, an example is given to illustrate the application of the results. 相似文献
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Exact invariants and adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system 总被引:1,自引:0,他引:1 下载免费PDF全文
The exact invariants and the adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system are studied. The relations between the invariants and the symmetries of the system are established. Based on the concept of higher-order adiabatic invariant of a mechanical system under the action of a small perturbation, the forms of the exact invariants and adiabatic invariants and the conditions for their existence are proved. Finally, the inverse problem of the perturbation to symmetries of the system is studied and an example is also given to illustrate the application of the results. 相似文献
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研究Birkhoff系统对称性的摄动与绝热不变量.给出了未受扰Birkhoff系统的Lie对称性导致的Hojman型精确不变量.基于力学系统的高阶绝热不变量的定义,研究在小扰动作用下Birkhoff系统Lie对称性的摄动,得到了系统的一类新型绝热不变量.举例说明结果的应用.
关键词:
Birkhoff系统
Lie对称性
摄动
绝热不变量 相似文献