Viscous fluid dynamics in Bianchi type-I universe with decaying cosmological term

Shukla B. K., Beesham A., SOFUOĞLU D., Dubey R., Mishra P.

International Journal of Geometric Methods in Modern Physics, 2025 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1142/s0219887825502263
  • Dergi Adı: International Journal of Geometric Methods in Modern Physics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Communication Abstracts, Metadex, zbMATH, Civil Engineering Abstracts
  • Anahtar Kelimeler: Bianchi I model, bulk viscosity, current acceleration of universe, dark energy, decaying cosmological parameter, shear viscosity
  • İstanbul Üniversitesi Adresli: Evet

Özet

This paper analyzes a robust parameterization of the deceleration parameter, which leads to the development of dark energy models showing very interesting features of the late-time accelerating universe. In this model, using the updated cosmic observational datasets, the tightness of the constraints is established based on a Bianchi type-I bulk viscous model with decaying cosmological term. The proposed model shows very good agreement with recent observational data. We find the best fit values of the model parameters through the MCMC method using CC, SNIa and BAO (DESIY1, and SDSS-IV) data. The constrained model values are analyzed to determine the key cosmological parameters, including the present deceleration parameter, the Hubble constant, and the transition redshift from deceleration to acceleration. Additionally, the evolution of the physical and geometrical parameters is traced by diagnostic analysis and illustrated by means of plots.