论文标题
形状空间上的经典力学的符合性降低
Symplectic Reduction of Classical Mechanics on Shape Space
论文作者
论文摘要
物理学研究的最重要目标之一是找到描述我们宇宙的最基本和普遍的理论。许多理论假设存在物理对象所在的绝对空间和时间,并发生了物理过程。但是,将时间与另一个对象的运动相对,例如摆的旋转数和对象的位置主要是相对于其他对象。本文的目标是解释如何使用关系主义原理(待述下文),可以在最基本的空间上制定经典力学,该空间可以摆脱绝对实体:形状空间。在形状空间上,仅考虑相对方向和子系统的长度。为了找出经典系统的形状如何随着时间的流逝而演变,将“对汉密尔顿系统的符合性降低”的方法扩展到包括比例转换,并且通过这种方式,相对于完整的相似性组,经典系统的降低。关系原理的有效性的必要要求是,改变系统的长度尺度,依赖长度的理论的所有参数,都会相应地改变。特别是,关系主义原则需要对经典物理学相互作用潜力的耦合常数进行正确的转换。因此,这导致了普朗克的测量单元的转换,这使我们能够以独特的方式得出形状空间的度量。在本文的稍后,我们将解释在形状空间上减少的哈密顿和象征性形式的推导。
One of the foremost goals of research in physics is to find the most basic and universal theories that describe our universe. Many theories assume the presence of an absolute space and time in which the physical objects are located and physical processes take place. However, it is more fundamental to understand time as relative to the motion of another object, e.g. the number of swings of a pendulum, and the position of an object primarily as relative to other objects. The goals of this paper is to explain, how using the principle of relationalism (to be introduced below), classical mechanics can be formulated on a most elementary space, which is freed from absolute entities: shape space. On shape space only the relative orientation and length of subsystems are taken into account. In order to find out how the shape of a classical system evolves in time, the method of "symplectic reduction of Hamiltonian systems" is extended to include scale transformations, and in this way the reduction of a classical system with respect to the full similarity group is achieved. A necessary requirement for the validity of the principle of relationalism is that changing the length scale of a system, all parameters of the theory that depend on the length, get changed accordingly. In particular, the principle of relationalism requires a proper transformation of the coupling constants of the interaction potentials in Classical Physics. This leads consequently to a transformation in Planck's measuring units, which enables us to derive a metric on shape space in a unique way. Later in this paper, we will explain the derivation of the reduced Hamiltonian and symplectic form on shape space.