标题： 因子排序和量子宇宙学中的大体积动力学 显示英文标题

标题： Factor ordering and large-volume dynamics in quantum cosmology

摘要： 量子宇宙学意味着对经典运动方程的修正，这可能导致与经典轨迹的显著偏离，尤其是在大爆炸奇点附近的高曲率区域。 原则上，即使在某些低曲率区域，如果这些修正在长时间的宇宙演化过程中累积，也可能变得显著。 因此，分析这些项是一个重要的问题，以确保理论表现出可接受的半经典行为。 本文提出了一个针对此类项的普遍搜索，作为具有自由无质量标量场的k=0各向同性量子宇宙学模型的有效方程中的修正。 具体来说，研究了这样的模型是否可以通过量子效应表现出坍缩，并且结果表明哈密顿约束中的因子顺序选择在这方面尤其相关。 因此，发展了一种对有效方程中因子顺序歧义的系统分析。 显示英文摘要

摘要： Quantum cosmology implies corrections to the classical equations of motion which may lead to significant departures from the classical trajectory, especially at high curvature near the big-bang singularity. Corrections could in principle be significant even in certain low-curvature regimes, provided that they add up during long cosmic evolution. The analysis of such terms is therefore an important problem to make sure that the theory shows acceptable semiclassical behavior. This paper presents a general search for terms of this type as corrections in effective equations for a k=0 isotropic quantum cosmological model with a free, massless scalar field. Specifically, the question of whether such models can show a collapse by quantum effects is studied, and it turns out that factor-ordering choices in the Hamiltonian constraint are especially relevant in this regard. A systematic analysis of factor-ordering ambiguities in effective equations is therefore developed.