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arXiv math-ph/0303020math-phcond-mat.stat-mechmath.MPquant-ph
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测试粒子与稀玻色气体相互作用的量子随机方程

Quantum stochastic equation for test particle interacting with dilute Bose gas

A. N. Pechen

摘要:

利用随机极限方法研究了测试粒子与稀玻色气体相互作用系统的长时间量子动力学。任意形状因子和任意的情况下,不一定平衡,准自由低密度态的玻色气体被认为是。从微观动力学出发,我们在低密度极限下导出了演化算符的量子白噪声方程。该方程等价于由强度为$S-1$的量子泊松过程驱动的量子随机方程,其中$S$是单粒子$S$矩阵。我们的方法的新颖之处在于,方程是直接推导出的,而不使用Fock-antiFock(或Gel'fand-Naimark-Segal)表示。我们的方法的优点是简单的推导的限制方程和代数的主字段和伊藤表不依赖于玻色气体的初始状态。引入了因果状态的概念。我们构建主字段(白噪声和数字运营商)描述的动力学在低密度极限,并证明了时间(因果)的字段运营商的收敛到主字段的因果状态的收敛。

英文摘要:

We use the stochastic limit method to study long time quantum dynamics of a test particle interacting with a dilute Bose gas. The case of arbitrary form-factors and an arbitrary, not necessarily equilibrium, quasifree low density state of the Bose gas is considered. Starting from microscopic dynamics we derive in the low density limit a quantum white noise equation for the evolution operator. This equation is equivalent to a quantum stochastic equation driven by a quantum Poisson process with intensity $S-1$, where $S$ is the one-particle $S$ matrix. The novelty of our approach is that the equations are derived directly in terms of correlators, without use of a Fock-antiFock (or Gel'fand-Naimark-Segal) representation. Advantages of our approach are the simplicity of derivation of the limiting equation and that the algebra of the master fields and the Ito table do not depend on the initial state of the Bose gas. The notion of a causal state is introduced. We construct master fields (white noise and number operators) describing the dynamics in the low density limit and prove the convergence of chronological (causal) correlators of the field operators to correlators of the master fields in the causal state.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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