Observational constraints on quintessence dark energy from a quadratic deceleration parametrization
MODERN PHYSICS LETTERS A, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1142/s0217732326502020
- Dergi Adı: MODERN PHYSICS LETTERS A
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, INSPEC, MathSciNet, zbMATH, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Technology Collection (ProQuest)
- İstanbul Üniversitesi Adresli: Evet
Özet
In this paper, we study the late-time cosmic expansion within a scalar-field dark energy framework in a spatially flat FLRW Universe by adopting a quadratic parametrization of the deceleration parameter q(z). This approach allows a controlled and analytical description of the transition from decelerated to accelerated expansion. The model parameters are constrained using MCMC analysis with combined CC, BAO, and standard candle data (SnIa, QSO, GRBs, and H-0 measurements). The results indicate a transition redshift z(tr similar or equal to 0.61) and a present-day value q(0)similar or equal to-0.77. The reconstructed equation-of-state parameter satisfies -1