论文标题
带有多个标量事物字段的哈密顿小组田地理论
Hamiltonian group field theory with multiple scalar matter fields
论文作者
论文摘要
在自然永恒的环境中定义量子重力的动力学的一种方法是在定量之前选择适当的自由度作为“时钟”。最近在小组场理论中引入了这种脱甲状管素化的概念，导致了哈密顿的公式，在该公式中，状态或操作员在自由无质量标量场中给出的时钟进化，类似于量子宇宙学中的deparametrication模型中发生的情况。在这里，我们将哈密顿群体域理论的构建扩展到具有多个标量物质字段的模型，与先前研究的案例相比，遇到了新功能和技术微妙。我们表明，对于这些更通用模型的有效宇宙学动力学将在大容量（如果合适的（非传播）初始条件）中的多个标量限制的一般相对性的弗里德曼动力学降低。在高能量下，我们发现对经典弗里德曼方程的校正与循环量子宇宙学中的形式相似。这些校正通过反弹导致通用的奇异性解决。对于一般初始条件，有效的宇宙学动力学对“时钟”字段和其他物质字段的处理方式不同，这与弗里德曼（Friedmann）的一般相对论的分歧。我们推测从不均匀性方面的可能解释。
One approach to defining dynamics for quantum gravity in a naturally timeless setting is to select a suitable matter degree of freedom as a 'clock' before quantisation. This idea of deparametrisation was recently introduced in group field theory leading to a Hamiltonian formulation in which states or operators evolve with respect to the clock given by a free massless scalar field, similar to what happens in deparametrised models in quantum cosmology. Here we extend the construction of Hamiltonian group field theory to models with multiple scalar matter fields, encountering new features and technical subtleties compared with the previously studied case. We show that the effective cosmological dynamics for these more general models reduce to the Friedmann dynamics of general relativity with multiple scalar fields in the limit of large volume, if suitable (non-generic) initial conditions are chosen. At high energy, we find corrections to the classical Friedmann equations whose form is similar to what is found in loop quantum cosmology. These corrections lead to generic singularity resolution by a bounce. For generic initial conditions, the effective cosmological dynamics treat the 'clock' field and other matter fields differently, in disagreement with the Friedmann dynamics of general relativity. We speculate on a possible interpretation in terms of inhomogeneities.
