共查询到20条相似文献,搜索用时 31 毫秒
1.
In this paper, a new kind of symmetry and its conserved quantities of a mechanical
system in phase space are studied. The definition of this new symmetry, i.e. a
Noether--Lie symmetry, is presented, and the criterion of this symmetry is also
given. The Noether conserved quantity and the generalized Hojman conserved quantity
of the Noether--Lie symmetry of the system are obtained. The Noether--Lie symmetry
contains the Noether symmetry and the Lie symmetry, and has more generalized
significance. 相似文献
2.
Noether-Mei Symmetry of Mechanical System in Phase Space 总被引:1,自引:0,他引:1
In this paper, a new kind of symmetry and its conserved
quantities of a mechanical system in phase space are studied.
The definition of this new symmetry, i.e., a Noether-Mei symmetry,
is presented, and the criterion of this symmetry is also given.
The Noether conserved quantity and the Mei conserved quantity
deduced from the Noether-Mei symmetry of the system are obtained.
Finally, two examples are given to illustrate the application of the results. 相似文献
3.
4.
A series of non-Noether conservative quantities and Mei symmetries of nonconservative systems
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In this paper Mei symmetry is introduced for a nonconservative system. The necessary and
sufficient condition for a Mei symmetry to be also a Lie symmetry is
derived. It is proved that the Mei symmetry leads to a non-Noether
conservative quantity via a Lie symmetry, and deduces a Lutzky conservative
quantity via a Lie point symmetry. 相似文献
5.
FANG Jian-Hui DING Ning WANG Peng 《理论物理通讯》2006,46(1):97-100
In this paper, a new symmetry and its conserved quantities of a mechanical system in phase space are studied. The defition of this new symmetry, i.e., a unified one is presented, and the criterion of this symmetry is also given. The Noether, the generalized Hojman and the Mei conserved quantities of the unified symmetry of the system are obtained. The unified symmetry contains the Noether, the Lie and the Mei symmetries, and has more generalized significance. 相似文献
6.
FANG Jian-Hui 《理论物理通讯》2006,46(7)
In this paper, a new symmetry and its conserved quantities of a mechanical system in phase space are studied. The definition of this new symmetry, i.e., a unified one is presented, and the criterion of this symmetry is also given. The Noether, the generalized Hojman and the Mei conserved quantities of the unified symmetry of the system are obtained. The unified symmetry contains the Noether, the Lie and the Mei symmetries, and has more generalized significance. 相似文献
7.
对一类完整系统的方程给出其Mei对称性的定义和判据.如果Mei对称性是Noether对称性,则可找到Noether守恒量.如果Mei对称性是Lie对称性,则可找到Hojman型守恒量.举例说明结果的应用.
关键词:
分析力学
完整系统
Mei对称性
守恒量 相似文献
8.
In this paper, the Lie symmetry algebra of the coupled
Kadomtsev--Petviashvili (cKP) equation is obtained by the classical Lie group method and
this algebra is shown to have
a Kac--Moody--Virasoro loop algebra structure. Then the general symmetry groups of the cKP
equation is also obtained by the symmetry group direct method which is proposed by Lou et al。 From the
general symmetry groups, the Lie symmetry group can be recovered and a group
of discrete transformations can be derived simultaneously. Lastly,
from a known simple solution of the cKP equation, we can easily obtain
two new solutions by the general symmetry groups. 相似文献
9.
Different from the symmetry breaking associated with a phase transition, which occurs when the controlling parameter is manipulated across a critical point, the symmetry breaking presented in this Letter does not need parameter manipulation. Instead, the system itself suddenly undergoes symmetry breaking at a certain time during its evolution, which is intrinsic symmetry breaking. Through a polymer model, it is revealed that the origin of the intrinsic symmetry breaking is nonlinearity, which produces instability at the instance when the evolution crosses an inflexion point, where this instability breaks the original symmetry. 相似文献
10.
11.
The Mei symmetry of Tzénoff equations under the infinitesimal transformations of groups is studied in this paper. The definition and the criterion equations of the symmetry are given. If the symmetry is a Noether symmetry, then the Noether conserved quantity of the Tzénoff equations can be obtained by the Mei symmetry. 相似文献
12.
13.
M. Ademollo L. Brink A. DAdda R. DAuria E. Napolitano S. Sciuto E. Del Giudice P. Di Vecchia S. Ferrara F. Gliozzi R. Musto R. Pettorino 《Physics letters. [Part B]》1976,62(1):105-110
The (infinite-dimensional) supersymmetry algebra in 1 + 1 space-time dimension is extended in order to incorporate, in a non-trivial way, an internal symmetry. It turns out that this requirement implies that the internal symmetry is realized as a local gauge symmetry. Moreover, it is possible to construct string-like models with this underlying symmetry, where colour confinement is exactly realized as a consequence of the gauge constraints. 相似文献
14.
It is well known that a local, unitary Poincaré-invariant 2D quantum field theory with a global scaling symmetry and a discrete non-negative spectrum of scaling dimensions necessarily has both a left and a right local conformal symmetry. In this Letter, we consider a chiral situation beginning with only a left global scaling symmetry and do not assume Lorentz invariance. We find that a left conformal symmetry is still implied, while right translations are enhanced either to a right conformal symmetry or a left U(1) Kac-Moody symmetry. 相似文献
15.
《Physica D: Nonlinear Phenomena》1988,32(3):423-436
Bifurcation in symmetric is typically associated with spontaneous symmetry breaking. That is, bifurcation is associated with new solution having less symmetry.In this paper we show that symmetry-increasing bifurcation in the discrete dynamics of symmetric mappings is possible (and is perhaps generic). The reason for these bifurcations may be understood as follows. The existence of one attractor in a system with symmetry gives rise to a family of conjugate attractors all related by symmetry. Typically, in computer experiments, what we see is a sequence of symmetry-breaking bifurcations leading to the existence of conjugate chaotic attractors. As the bifurcation parameter is varied these attractors grow in size and merge leading to a single attractor having greater symmetry.We prove a theorem suggesting why this new attractor should have greater symmetry and present a number of striking examples of the symmetric patterns that can be formed by iterating the simplest mappings on the plane with the symmetry of the regular m-gon. In the last section we discuss period-doubling in the presence of symmetry. 相似文献
16.
17.
Noether symmetry and Lie symmetry of discrete holonomic systems with dependent coordinates
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The Noether symmetry, the Lie symmetry and the conserved quantity of discrete holonomic systems with dependent coordinates are investigated in this paper. The Noether symmetry provides a discrete Noether identity and a conserved quantity of the system. The invariance of discrete motion equations under infinitesimal transformation groups is defined as the Lie symmetry, and the condition of obtaining the Noether conserved quantity from the Lie symmetry is also presented. An example is discussed to show the applications of the results. 相似文献
18.
Based on the weak Noether symmetry proposed by Mei F X, this paper discusses the weak Noether symmetry for nonholonomic system of non-Chetaev type, and presents expressions of three kinds of conserved quantities by weak Noether symmetry. Finally, the application of this new results is showed by a practical example. 相似文献
19.
A symmetry and a conserved quantity of the Birkhoff system are studied. The
symmetry is called the Birkhoff symmetry. Its definition and criterion are
given in this paper. A conserved quantity can be deduced by using the
symmetry. An example is given to illustrate the application of the result. 相似文献