标题： 超越边界条件：一般的宇宙学理论 显示英文标题

标题： Beyond Boundary Conditions: General Cosmological Theories

摘要： 时间对称的宇宙学理论，在这些理论中初始状态和最终状态被安排成具有相似的特征或者被独立确定，已经在文献中被广泛讨论。 然而，一种更普遍且可能更有用的可能性似乎出乎意料地从未被考虑过。 量子宇宙学，像任何本质上具有概率性的动力学理论一样，可以通过对一系列事先固定并独立于哈密顿量和初始状态的宇宙事件的发生进行条件限定来修改。 这些更一般的理论提供了一类自然的替代方案，最终应该有助于量化数据在多大程度上支持初始条件就足够这一假设。 显示英文摘要

摘要： Time-symmetric cosmological theories, in which the initial and final states are arranged to have similar features or are independently fixed, have been quite extensively discussed in the literature. However, a more general and perhaps more useful possibility seems, surprisingly, never to have been considered. Quantum cosmology, like any inherently probabilistic dynamical theory, can be modified by conditioning on the occurrence of a sequence of cosmological events fixed a priori and independently of the hamiltonian and initial state. These more general theories provide a natural class of alternatives which should eventually be useful in quantifying how well the hypothesis that initial conditions suffice is supported by the data.