共查询到18条相似文献,搜索用时 93 毫秒
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研究当存在边界的情形下 Dirac场的正则量子化问题. 采用文献[1]的观点, 将边界条件当作Dirac初级约束.与已有研究不同的是, 本文从离散的角度研究此问题. 将Dirac场的拉氏量和内在约束进行离散化, 并且将离散的边界条件当作初级Dirac约束. 因此, 从约束的起源来看, 这个模型中存在两种不同的约束: 一种是由于模型的奇异性而带来的约束, 即内在约束; 另一种是边界条件. 在对此模型进行正则量子化过程中提出一种能够平等地处理内在约束和边界条件的方法. 为了证明该方法能够平等地对待这两种起源不同的约束, 在计算Dirac 括号时分别选取了两个不同的子集合来构造"中间Dirac括号", 最后得到了相同的结果.
关键词:
边界条件
Dirac约束
Dirac括号 相似文献
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研究奇异系统Hamilton正则方程的形式不变性即Mei对称性,给出其定义、确定方程、限制方程和附加限制方程.研究奇异系统Hamilton正则方程的Mei对称性与Noether对称性、Lie对称性之间的关系,寻求系统的守恒量.给出一个例子说明结果的应用.
关键词:
奇异系统
Hamilton正则方程
约束
对称性
守恒量 相似文献
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本文导出场论中用奇异拉氏量描述的系统正则形式的广义Noether第一定理(GNFT),导出无限连续群下变更性系统正则形式的广义Noether恒等式(GNI),讨论了它们在Dirac约束理论中的应用。给出一个新的反倒,说明Dirac猜想失效,指出某些变更性系统也具有Dirac约束,讨论了GNI在色动力学中的应用。
关键词: 相似文献
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采用薄层模型brick-wall方法,计算了一般球对称带电蒸发黑洞Dirac场的熵,通过适当选择时间依赖的截断因子,仍可得出黑洞熵与视界面积成正比的结论.
关键词:
熵
蒸发黑洞
薄层模型
Dirac场
Dirac方程 相似文献
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研究Hamilton系统的形式不变性即Mei对称性,给出其定义和确定方程.研究Hamilton系统的Mei对称性与Noether对称性、Lie对称性之间的关系,寻求系统的守恒量.给出一个例子说明本文结果的应用.
关键词:
Hamilton系统
Mei对称性
Noether对称性
Lie对称性
守恒量 相似文献
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陈刚 《原子与分子物理学报》2001,18(4):470-472
在标量型和矢量型Morse势相等的条件下,给出了Dirac方程束缚态的一维二分量波函数和一维四分量波函数的精确解.并且在求精确解时,运用一种新的自变量变换方法,使方程求解变得比较简单. 相似文献
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The extended canonical Noether identities and canonical first Noether
theorem derived from an extended action in phase space for a system with a
singular Lagrangian are formulated. Using these canonical Noether
identities, it can be shown that the constraint multipliers connected with
the first-class constraints may not be independent, so a query to a
conjecture of Dirac is presented. Based on the symmetry properties of the
constrained Hamiltonian system in phase space, a counterexample to a
conjecture of Dirac is given to show that Dirac's conjecture
fails in such a system. We present here a different way rather than
Cawley's examples and other's ones in that there is no
linearization of constraints in the problem. This example has a feature that
neither the primary first-class constraints nor secondary first-class
constraints are generators of the gauge transformation. 相似文献
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We discuss the stationarity of generator G for gauge symmetries in two directions.One is to the motion equations defined by total Hamiltonian HT,and gives that the number of the independent coefficients in the generator G is not greater than the number of the primary first-class constraints,and the number of Noether conserved charges is not greater than that of the primary first-class constraints,too.The other is to the variances of canonical variables deduced from the generator G,and gives the variances of Lagrangian multipliers contained in extended Hamiltonian HE.And a second-class constraint generated by a first-class constraint may imply a new first-class constraint which can be combined by introducing other second-class constraints.Finally,we supply two examples.One with three first-class constraints (two is primary and one is secondary) has two Noether conserved charges,and the secondary first-class constraint is combined by three second-class constraints which are a secondary and two primary second-class constraints.The other with two first-class constraints (one is primary and one is secondary) has one Noehter conserved charge. 相似文献
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Dirac‘s method which itself is for constrained Boson fields and particle systems is followed and developed to treat Dirac fields in light-front coordinates. 相似文献
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Elena Castellani 《International Journal of Theoretical Physics》2004,43(6):1503-1514
We examine the relevance of Dirac's view on the use of transformation theory and invariants in modern physics to current reflections on the meaning of physical symmetries, especially gauge symmetries. 相似文献
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Systems with singular-higher order Lagrangians are investigated by two methods: Dirac method and Hamilton-Jacobi method. An example is studied and it is shown that the Hamilton-Jacobi method gives the correct canonical generalized equations of motion, contrary to Dirac method, where Dirac conjecture is invalid. 相似文献
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Yong-Long Wang Zi-Ping Li Ke Wang 《International Journal of Theoretical Physics》2009,48(7):1894-1904
The gauge symmetries of a constrained system can be deduced from the gauge identities with Lagrange method, or the first-class
constraints with Hamilton approach. If Dirac conjecture is valid to a dynamic system, in which all the first-class constraints
are the generators of the gauge transformations, the gauge transformations deduced from the gauge identities are consistent
with these given by the first-class constraints. Once the equivalence vanishes to a constrained system, in which Dirac conjecture
would be invalid. By using the equivalence, two counterexamples and one example to Dirac conjecture are discussed to obtain
defined results. 相似文献
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A fundamental problem regarding the Dirac quantization of a free particle on an () curved hypersurface embedded in N flat space is the impossibility to give the same form of the curvature‐induced quantum potential, the geometric potential as commonly called, as that given by the Schrödinger equation method where the particle moves in a region confined by a thin‐layer sandwiching the surface. This problem is resolved by means of a previously proposed scheme that hypothesizes a simultaneous quantization of positions, momenta, and Hamiltonian, among which the operator‐ordering‐free section is identified and is then found sufficient to lead to the expected form of geometric potential. 相似文献
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It is shown that a Dirac bracket algebra is isomorphic to the original Poisson bracket algebra of first-class functions subject to first-class constraints. The isomorphic image of the Dirac bracket algebra in the star-product commutator algebra is found. 相似文献