Observational constraints on scalar-nonmetricity cosmology: the role of the connection
Abstract
Scalar-nonmetricity gravity provides a natural scalar-tensor extension of symmetric teleparallel gravity, with the gravitational interaction encoded in nonmetricity. A distinctive feature is that, even for a spatially flat Friedmann-Robertson-Walker geometry, three inequivalent symmetric-teleparallel connection branches are allowed. Whether this geometrical freedom has observable consequences is therefore an important question. In this work we perform a systematic observational comparison of all three connection branches, considering a steep scalar-field potential and a power-law nonminimal coupling. We constrain the models using combinations of Pantheon Plus and DES Year 5 Type Ia supernovae, DESI DR2 baryon acoustic oscillations, and compressed cosmic microwave background information. We find that all three branches can reproduce the transition from matter domination to late-time acceleration, but their observational behavior is connection dependent. Connection I exhibits the strongest sensitivity to the supernova compilation, Connection II yields remarkably stable reconstructed histories, while Connection III shows an intermediate behavior. Most notably, for DES Y5+CMB+DESI DR2, Connection I gives Δχ2min=−13.99 and ΔAIC=−5.99 relative to ΛCDM, and is therefore favored by the Akaike information criterion.
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BibTeX
@misc{murtaza2026observational,
title = {{Observational constraints on scalar-nonmetricity cosmology: the role of the connection}},
author = {Ghulam Murtaza and Avik De and Emmanuel N. Saridakis},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.24402},
eprint = {2610.24402},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.24402},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Observational constraints on scalar-nonmetricity cosmology: the role of the connection
AU - Ghulam Murtaza
AU - Avik De
AU - Emmanuel N. Saridakis
PY - 2026
DA - 2026/10/17
PB - arXiv
DO - 10.48550/arxiv.2610.24402
UR - https://arxiv.org/abs/2610.24402
AB - Scalar-nonmetricity gravity provides a natural scalar-tensor extension of symmetric teleparallel gravity, with the gravitational interaction encoded in nonmetricity. A distinctive feature is that, even for a spatially flat Friedmann-Robertson-Walker geometry, three inequivalent symmetric-teleparallel connection branches are allowed. Whether this geometrical freedom has observable consequences is therefore an important question. In this work we perform a systematic observational comparison of all three connection branches, considering a steep scalar-field potential and a power-law nonminimal coupling. We constrain the models using combinations of Pantheon Plus and DES Year 5 Type Ia supernovae, DESI DR2 baryon acoustic oscillations, and compressed cosmic microwave background information. We find that all three branches can reproduce the transition from matter domination to late-time acceleration, but their observational behavior is connection dependent. Connection I exhibits the strongest sensitivity to the supernova compilation, Connection II yields remarkably stable reconstructed histories, while Connection III shows an intermediate behavior. Most notably, for DES Y5+CMB+DESI DR2, Connection I gives Δχ^2_min=−13.99 and ΔAIC=−5.99 relative to ΛCDM, and is therefore favored by the Akaike information criterion.
ER -