DESI and Dynamical Dark Energy from Extended Pre-geometric Gravity
Abstract
We consider the simplest quadratic extension of MacDowell--Mansouri pre-geometric gravity that preserves the topological pre-volume-form symmetry. Upon symmetry breaking, the theory reduces to (Lovelock)2 gravity and admits a Galileon-like Horndeski scalar-tensor representation. The gravitational Higgs mechanism relates the Gauss--Bonnet coupling to the bare cosmological constant, while the quadratic correction elevates the gravitational θ-angle to a dynamical gravi-axion whose ultra-light mass scale can drive late-time acceleration. We confront the Jordan-frame background with DESI DR2 baryon-acoustic-oscillation measurements and an auxiliary six-point compressed growth diagnostic. A transient dark-energy response localized near H≃ mb (mb the effective gravi-axion mass) reproduces the fitted expansion and its BAO-distance predictions and becomes negligible at high redshift. For the full linear calculation, we combine a smooth positive-density representative of this response class with explicitly imposed GR-like tensor and local sectors, together with the parameterized post-Friedmann prescription. The resulting gravi-axion benchmark exhibits a transient effective phantom crossing and admits a regular full linear CAMB evolution. Its separate likelihood contributions are promising relative to those obtained from the flat-ΛCDM baseline for the same data set. These results establish the dynamical gravi-axion framework, dual to MacDowell--Mansouri pre-geometric gravity, as a viable effective quantum-gravity inspired description of late-time cosmology, motivating further investigation into its fundamental origin and perturbative consistency.
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BibTeX
@misc{addazi2026desi,
title = {{DESI and Dynamical Dark Energy from Extended Pre-geometric Gravity}},
author = {Andrea Addazi and Yermek Aldabergenov and Daulet Berkimbayev and Yifu Cai and Salvatore Capozziello and Giuseppe Meluccio},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.07344},
eprint = {2605.07344},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.07344},
}
RIS
TY - UNPB
TI - DESI and Dynamical Dark Energy from Extended Pre-geometric Gravity
AU - Andrea Addazi
AU - Yermek Aldabergenov
AU - Daulet Berkimbayev
AU - Yifu Cai
AU - Salvatore Capozziello
AU - Giuseppe Meluccio
PY - 2026
DA - 2026/09/17
PB - arXiv
DO - 10.48550/arxiv.2605.07344
UR - https://arxiv.org/abs/2605.07344
AB - We consider the simplest quadratic extension of MacDowell--Mansouri pre-geometric gravity that preserves the topological pre-volume-form symmetry. Upon symmetry breaking, the theory reduces to (Lovelock)^2 gravity and admits a Galileon-like Horndeski scalar-tensor representation. The gravitational Higgs mechanism relates the Gauss--Bonnet coupling to the bare cosmological constant, while the quadratic correction elevates the gravitational θ-angle to a dynamical gravi-axion whose ultra-light mass scale can drive late-time acceleration. We confront the Jordan-frame background with DESI DR2 baryon-acoustic-oscillation measurements and an auxiliary six-point compressed growth diagnostic. A transient dark-energy response localized near H≃ m_b (m_b the effective gravi-axion mass) reproduces the fitted expansion and its BAO-distance predictions and becomes negligible at high redshift. For the full linear calculation, we combine a smooth positive-density representative of this response class with explicitly imposed GR-like tensor and local sectors, together with the parameterized post-Friedmann prescription. The resulting gravi-axion benchmark exhibits a transient effective phantom crossing and admits a regular full linear CAMB evolution. Its separate likelihood contributions are promising relative to those obtained from the flat-ΛCDM baseline for the same data set. These results establish the dynamical gravi-axion framework, dual to MacDowell--Mansouri pre-geometric gravity, as a viable effective quantum-gravity inspired description of late-time cosmology, motivating further investigation into its fundamental origin and perturbative consistency.
ER -