论文标题
Wigner的朋友悖论:与弱势和弱小现实主义模型的一致性
Wigner's Friend paradoxes: consistency with weak-contextual and weak-macroscopic realism models
论文作者
论文摘要
储层计算是预测湍流的有力工具,其简单的架构具有处理大型系统的计算效率。然而,其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间,然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用,该系统模拟了湍流的若干特征。我们表明,使用径向基函数作为非线性投影器,即使只有部分观测并且不知道控制方程,也能稳健地捕捉复杂的系统非线性。最后,我们表明,当测量稀疏、不完整且带有噪声,甚至控制方程变得不准确时,我们的网络仍然可以产生相当准确的预测,从而为实际湍流系统的无模型预测铺平了道路。
Wigner's friend paradoxes highlight contradictions between measurements made by Friends inside a laboratory and superobservers outside a laboratory, who have access to an entangled state of the measurement apparatus. The contradictions lead to no-go theorems for observer-independent facts, thus challenging concepts of objectivity. Here, we examine the paradoxes from the perspective of establishing consistency with macroscopic realism. We present versions of the Brukner-Wigner-friend and Frauchiger-Renner paradoxes in which the spin-$1/2$ system measured by the Friends corresponds to two macroscopically distinct states. The local unitary operations $U_θ$ that determine the measurement setting $θ$ are carried out using nonlinear interactions, thereby ensuring measurements need only distinguish between the macroscopically distinct states. The macroscopic paradoxes are perplexing, seemingly suggesting there is no objectivity in a macroscopic limit. However, we demonstrate consistency with a contextual weak form of macroscopic realism (wMR): The premise wMR asserts that the system can be considered to have a definite spin outcome $λ_θ$, at the time after the system has undergone the unitary rotation $U_θ$ to prepare it in a suitable pointer basis. We further show that the paradoxical outcomes imply failure of deterministic macroscopic local realism, and arise when there are unitary interactions $U_θ$ occurring due to a change of measurement setting at both sites, with respect to the state prepared by each Friend. In models which validate wMR, there is a breakdown of a subset of the assumptions that constitute the Bell-Locality premise. A similar interpretation involving a weak contextual form of realism exists for the original paradoxes.