Year: 2026
Type: preprint
Abstract: 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.
Source: arXiv (Cornell University)
Authors: Granata, Daniele, Oriti, Daniele
Language: English
Subfield: Statistical and Nonlinear Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: WithOut SpaceTime (WOST)
OpenAlex ID: W7214713011