arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2011.02867quant-phcond-mat.dis-nncond-mat.stat-mechhep-th
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概率世界

The probabilistic world

C. Wetterich

AI总结:

本文论证覆盖全部时间的整体概率分布可通过局域时间概率信息导出量子形式,并说明概率元胞自动机等价于离散时间量子系统,从而解释 Bell 不等式的适用限制。

摘要:

物理学将概率作为数学描述的基本实体。可观测对象的期望值依据经典统计规则计算。单一世界的整体概率分布覆盖所有时刻。一旦人们关注局域于时间的概率信息的演化,量子形式体系便会出现。波函数或密度矩阵使人们能够为经典统计表述一条普遍的线性演化定律。经典统计的量子形式体系是一种强有力的工具,使我们能够为广义 Ising 模型引入动量可观测对象及其相关的 Fourier 表示。将算符与可观测对象关联起来,便可以利用密度矩阵、按照通常的量子规则计算期望值。我们表明,概率元胞自动机在采用离散时间步和实波函数的表述中就是量子系统。借助复结构,自动机的演化算符可以用一个包含费米子产生和湮灭算符的 Hamiltonian 来表示。局域于时间的概率信息相当于整体概率系统的一个子系统,该子系统与其由过去和未来构成的环境相关联。这类子系统通常涉及概率性可观测对象,对于这些对象,只能获得其可能测量值的概率分布。不完备统计不允许计算任意子系统可观测对象的经典关联函数。Bell 不等式并非普遍适用。

英文摘要:

Physics is based on probabilities as fundamental entities of a mathematical description. Expectation values of observables are computed according to the classical statistical rule. The overall probability distribution for one world covers all times. The quantum formalism arises once one focuses on the evolution of the time-local probabilistic information. Wave functions or the density matrix allow the formulation of a general linear evolution law for classical statistics. The quantum formalism for classical statistics is a powerful tool which allows us to implement for generalized Ising models the momentum observable with the associated Fourier representation. The association of operators to observables permits the computation of expectation values in terms of the density matrix by the usual quantum rule. We show that probabilistic cellular automata are quantum systems in a formulation with discrete time steps and real wave functions. With a complex structure the evolution operator for automata can be expressed in terms of a Hamiltonian involving fermionic creation and annihilation operators. The time-local probabilistic information amounts to a subsystem of the overall probabilistic system which is correlated with its environment consisting of the past and future. Such subsystems typically involve probabilistic observables for which only a probability distribution for their possible measurement values is available. Incomplete statistics does not permit to compute classical correlation functions for arbitrary subsystem-observables. Bell's inequalities are not generally applicable.

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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