摘要
提出了相对论性力学系统的一种新的对称性,并给出了此对称性导致的守恒量.提出了相对论性力学系统的Birkhoff对称性,即对应于相对论性力学系统的一组Birkhoff动力学函数的运动微分方程的解都满足从另一组Birkhoff动力学函数得到的运动微分方程.证明了与两组Birkhoff动力学函数分别给出的相对论性Birkhoff方程相关联的系数矩阵的各次幂的迹是系统的一个守恒量,从而将Currie和Saletan提出的力学系统的等效Lagrange函数定理拓展到了相对论性Birkhoff动力学系统.给出了两个例子以说明结果的正确性.
A new symmetry of a relativistic mechanical system is put forward, and the corresponding conserved quantity is given. The new symmetry is defined in such a way that if each solution to the differential equations of motion of a relativistic mechanical system corresponding to a set of Birkhoff's dynamical functions satisfies the differential equations of motion obtained by other set of Birkhoff's dynamical functions and vice versa, then the corresponding invariance is called a symmetry of Birkhoffians. We prove that the coefficient matrix which relates to the relativistic Birkhoff's equations obtained from two sets of Birkhoff's dynamical functions, is such that the trace of all its integer powers is a conserved quantity of the system, and therefore a theorem known for nonsingular equivalent Lagrangians presented by Currie and Saletan is extended to a relativistic Birkhoffian system. Two examples are given to illustrate the application of the results.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第21期299-304,共6页
Acta Physica Sinica
基金
国家自然科学基金(批准号:10972151
11272227)资助的课题~~