发表机构
Sapienza University of Rome; Universidad Complutense de Madrid（罗马第一大学; 马德里康普顿斯大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在群场论凝聚体宇宙学框架下，通过均场近似和厄米相互作用推导有效动力学，证明系统渐近趋近德西特态，并可由相位及次主导模式产生偏离w=-1的动力学暗能量，包括幻影行为，且额外标量场影响穿越条件。
AI 中文摘要
我们在群场论（GFT）凝聚体宇宙学的框架内，研究了从量子引力中涌现的动力学暗能量。我们通过考虑更广泛的参数空间，推广了先前由量子引力诱导的宇宙加速模型，其中除关系时钟外还包含一个额外的标量物质场，并同时考虑了相位动力学以及多个凝聚体模式的贡献。在采用相干尖峰态的均场近似下，并限制为厄米GFT相互作用，我们推导了相应的有效宇宙学动力学，并分析了其晚期行为。我们表明，该系统趋近于渐近德西特区域，该区域由单一凝聚体模式动态主导，而趋近该区域的过程可以表现出非平凡的动力学暗能量演化。特别是，凝聚体相位和次主导模式都能产生对渐近状态方程$w=-1$的偏离，包括幻影行为，并且在适当条件下，能穿越幻影分界线。额外的标量物质场直接进入这些条件，从而在物质内容与量子引力诱导的暗能量动力学之间建立了联系。这些结果扩展了GFT机制用于动力学暗能量的稳健性和普适性，并为将底层量子引力动力学与宇宙学观测相对照提供了基础。
英文摘要
We investigate dynamical dark energy emerging from quantum gravity within the framework of group field theory (GFT) condensate cosmology. We generalise previous models of quantum gravity induced cosmic acceleration by considering a broader parameter space, including an additional scalar matter field besides the relational clock, and accounting simultaneously for the phase dynamics and the contribution of multiple condensate modes. Working in a mean-field approximation with coherent peaked states and restricting to Hermitian GFT interactions, we derive the corresponding effective cosmological dynamics and analyse its late-time behaviour. We show that the system approaches an asymptotic de Sitter regime, dynamically dominated by a single condensate mode, while the approach to this regime can exhibit a non-trivial dynamical dark-energy evolution. In particular, both the condensate phase and subdominant modes can generate deviations from the asymptotic equation of state $w=-1$, including phantom behaviour and, under suitable conditions, a crossing of the phantom divide. The additional scalar matter field enters directly into these conditions, providing a link between the matter content and the quantum gravity induced dark-energy dynamics. These results extend the robustness and generality of the GFT mechanism for dynamical dark energy and provide a basis for confronting the underlying quantum gravity dynamics with cosmological observations.
