Cosmological Perturbations and Observational Constraints on Spinor Field Quintessence Dark Energy
Abstract
We investigate the linear perturbation cosmology of a spinor-field realization of quintessence dark energy by implementing the model in the Einstein--Boltzmann solver \texttt{CLASS}. The model parameters are constrained using a Markov Chain Monte Carlo analysis with Pantheon+ Type Ia supernovae, cosmic chronometers, DESI DR2 baryon acoustic oscillations, redshift-space distortions, and Planck 2018 CMB distance-prior data. For the full combined dataset, we obtain wde=−0.9710+0.0206−0.0206, Ωm0=0.2939+0.0047−0.0047, and H0=66.23+0.55−0.53,kms−1Mpc−1. The corresponding perturbation quantities are σ8=0.7537+0.0076−0.0075 and S8=0.7459+0.0067−0.0065. We find that the spinor-quintessence model closely reproduces the predictions of a phenomenological constant-w model in the matter power spectrum, growth-rate observable fσ8, growth index, and CMB temperature anisotropy spectrum, with deviations generally below the percent level. A comparison with ΛCDM and wCDM shows statistically indistinguishable fits, although the Bayesian information criterion favors the simpler ΛCDM model. Our results demonstrate that the spinor-field quintessence scenario remains consistent with current expansion-history and structure-growth observations when its perturbation evolution is treated consistently, providing a field-theoretically motivated realization of constant-w dark energy at the background and linear perturbation levels.
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BibTeX
@misc{goray2026cosmological,
title = {{Cosmological Perturbations and Observational Constraints on Spinor Field Quintessence Dark Energy}},
author = {Mahendra Goray},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.00041},
eprint = {2609.00041},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.00041},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Cosmological Perturbations and Observational Constraints on Spinor Field Quintessence Dark Energy
AU - Mahendra Goray
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.00041
UR - https://arxiv.org/abs/2609.00041
AB - We investigate the linear perturbation cosmology of a spinor-field realization of quintessence dark energy by implementing the model in the Einstein--Boltzmann solver \texttt{CLASS}. The model parameters are constrained using a Markov Chain Monte Carlo analysis with Pantheon^+ Type Ia supernovae, cosmic chronometers, DESI DR2 baryon acoustic oscillations, redshift-space distortions, and Planck 2018 CMB distance-prior data. For the full combined dataset, we obtain w_de=−0.9710^+0.0206_−0.0206, Ω_m0=0.2939^+0.0047_−0.0047, and H_0=66.23^+0.55_−0.53,kms^−1Mpc^−1. The corresponding perturbation quantities are σ_8=0.7537^+0.0076_−0.0075 and S_8=0.7459^+0.0067_−0.0065. We find that the spinor-quintessence model closely reproduces the predictions of a phenomenological constant-w model in the matter power spectrum, growth-rate observable fσ_8, growth index, and CMB temperature anisotropy spectrum, with deviations generally below the percent level. A comparison with ΛCDM and wCDM shows statistically indistinguishable fits, although the Bayesian information criterion favors the simpler ΛCDM model. Our results demonstrate that the spinor-field quintessence scenario remains consistent with current expansion-history and structure-growth observations when its perturbation evolution is treated consistently, providing a field-theoretically motivated realization of constant-w dark energy at the background and linear perturbation levels.
ER -