共查询到20条相似文献,搜索用时 82 毫秒
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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
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讨论了构造Birkhoff表示的Hojman方法.利用该方法重新研究Birkhoff对称性,提出一种关于该对称性的新见解,给出Birkhoff守恒量的新证明,并对该守恒量仅与Birkhoff张量相关作出解释.举例说明所得结果的应用. 相似文献
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研究了非完整力学系统的一种新对称性——Noether-Lie对称性及其守恒量. 给出了非完整力学系统Noether -Lie对称性的定义和判据,提出系统的Noether-Lie对称性导致Noether守恒量和广义Hojman守恒量的定理. 举例说明了结果的应用. Hojman守恒量是所给出的广义Hojman守恒量的特例.
关键词:
非完整力学系统
Noether-Lie对称性
Noether守恒量
广义Hojman守恒量 相似文献
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研究事件空间中Birkhoff系统的Noether对称性与Noether守恒量.首先,建立了事件空间中Birkhoff系统的参数方程;其次,基于Pfaff作用量在无限小变换下的不变性,给出了事件空间中Birkhoff系统的Noether定理及其逆定理;最后,举例说明结果的应用.
关键词:
事件空间
Birkhoff系统
Pfaff作用量
Noether对称性 相似文献
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A geometrical approach to the Hojman theorem of a rotational relativistic Birkhoffian system is presented.The differential equations of motion of the system are established. According to the invariance of differential equations under infinitesimal transformation, the determining equations of Lie symmetry are constructed. A new conservation law of the system, called Hojman theorem, is obtained, which is the generalization of previous results given sequentially by Hojman, Zhang, and Luo et al. In terms of the theory of modern differential geometry a proof of the theorem is given. 相似文献
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A geometrical approach to the Hojman theorem of a rotational relativistic Birkhoffian system is presented.The differential equations of motion of the system are established. According to the invariance of differential equations under infinitesimal transformation, the determining equations of Lie symmetry are constructed. A new conservation law of the system, called Hojman theorem, is obtained, which is the generalization of previous results given sequentially by Hojman, Zhang, and Luo et al. In terms of the theory of modern differential geometry a proof of the theorem is given. 相似文献
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M. Crampin 《Physics letters. A》1983,95(5):209-212
It is shown that various recent results on the existence of constants of motion not arising directly from Noether's theorem or similar considerations, such as the result of Hojman and Harleston for systems with alternative lagrangian formulations, are consequences of some rather simple and general facts of differential geometry. 相似文献
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Hojman conserved quantity for nonholonomic systems of unilateral non-Chetaev type in the event space 下载免费PDF全文
Hojman conserved quantities deduced from the special Lie symmetry,
the Noether symmetry and the form invariance for a nonholonomic
system of the unilateral non-Chetaev type in the event space are
investigated. The differential equations of motion of the system
above are established. The criteria of the Lie symmetry, the Noether
symmetry and the form invariance are given and the relations between
them are obtained. The Hojman conserved quantities are gained by
which the Hojman theorem is extended and applied to the nonholonomic
system of the unilateral non-Chetaev type in the event space. An
example is given to illustrate the application of the results. 相似文献
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研究了事件空间中非Chetaev型非完整约束系统由特殊的Lie对称性、Noether对称性和Mei对称性导致的Hojman守恒量.建立了系统的运动微分方程.给出了Lie对称性、Noether对称性和Mei对称性的判据,研究了三种对称性间的关系.将Hojman定理推广并应用于事件空间中的非Chetaev型非完整约束系统,得到Hojman守恒量.并举出一例说明结论的应用.
关键词:
事件空间
非Chetaev型非完整约束系统
对称性
Hojman守恒量 相似文献
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Special Lie Symmetry and Hojman Conserved Quantity of Appell Equations for a Holonomic System 总被引:3,自引:0,他引:3 下载免费PDF全文
Special Lie symmetry and Hojman conserved quantity of Appell equations for a holonomic system are studied. Appell equations and differential equations of motion for holonomic mechanic systems are established. Under special Lie infinitesimal transformations in which the time is invariable, the determining equation of the special Lie symmetry and the expressions of Hojman conserved quantity for Appell equations of holonomic systems are presented. Finally, an example is given to illustrate the application of the results. 相似文献
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Mei symmetry and generalized Hojman conserved quantity for variable mass systems with unilateral holonomic constraints 下载免费PDF全文
This paper studies Mei symmetry which leads to a generalized Hojman
conserved quantity for variable mass systems with unilateral
holonomic constraints. The differential equations of motion for the
systems are established, the definition and criterion of the Mei
symmetry for the systems are given. The necessary and sufficient
condition under which the Mei symmetry is a Lie symmetry for the
systems is obtained and a generalized Hojman conserved quantity
deduced from the Mei symmetry is got. An example is given to
illustrate the application of the results. 相似文献