论文标题
积极宇宙常数对环路量子宇宙学的反弹的影响
The Effect of a positive cosmological constant on the bounce of Loop Quantum Cosmology
论文作者
论文摘要
在循环量子宇宙学的背景下，我们为在存在小且正面的宇宙学常数的情况下，在存在小且正面的宇宙学常数的情况下，在fly friedmann-Lema-Walker模型的量子动力学方面提供了一个分析解决方案。我们在没有宇宙常数的情况下对模型使用扰动处理，这是可以解决的。我们的解决方案是近似的，但是在高曲率校正很重要的高曲率方向上是有效的。我们明确计算体积期望值的演变。对于以高斯光谱曲线为特征的半经典状态，引入正宇宙常数可溶解模型的弹跳到较低的体积和较高的标量场值。这些位移取决于状态，特别是它们取决于高斯轮廓的峰值，该峰值测量了标量场的动量。此外，对于那些半经典状态，弹跳仍然是对称的，如消失的宇宙恒定情况。但是，我们表明该体积的行为对于通用状态而言更为复杂，这通常导致非对称反弹。
We provide an analytical solution to the quantum dynamics of a flat Friedmann-Lemaître- Robertson-Walker model with a massless scalar field in the presence of a small and positive cosmological constant, in the context of Loop Quantum Cosmology. We use a perturbative treatment with respect to the model without a cosmological constant, which is exactly solvable. Our solution is approximate, but it is precisely valid at the high curvature regime where quantum gravity corrections are important. We compute explicitly the evolution of the expectation value of the volume. For semiclassical states characterized by a Gaussian spectral profile, the introduction of a positive cosmological constant displaces the bounce of the solvable model to lower volumes and to higher values of the scalar field. These displacements are state dependent, and in particular, they depend on the peak of the Gaussian profile, which measures the momentum of the scalar field. Moreover, for those semiclassical states, the bounce remains symmetric, as in the vanishing cosmological constant case. However, we show that the behavior of the volume is more intricate for generic states, leading in general to a non-symmetric bounce.
