Phenomenology of Λ-CDM Model: A Possibility of Accelerating Universe with Positive Pressure

2007/11/30 by Saibal Ray, Maxim Khlopov, Partha Pratim Ghosh +1 · 31 citations
Engineering · Physics and Astronomy · #Advanced Mathematical Theories and Applications #COSMIC cancer database #Cosmological model #Cosmology and Gravitation Theories #Deceleration parameter #Material Science and Thermodynamics #Metric expansion of space #Phenomenological model #Phenomenology (philosophy) #Sign (mathematics) #Universe #astro-ph.CO #gr-qc

paper · pdf · doi:10.1007/s10773-010-0639-0

published in International Journal of Theoretical Physics 50(3), 939-951 (Springer Science+Business Media) · 16 Latex pages, 11 figures, Considerable modifications in the text; Accepted in IJTP

arxiv created 2010/12/14 · openalex publication_date 2010/12/28 · arxiv updated 2011/01/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

Among various phenomenological Λ models, a time-dependent model Λ∼ H³ is selected here to investigate the Λ-CDM cosmology. Using this model the expressions for the time-dependent equation of state parameter ω and other physical parameters are derived. It is shown that in H³ model accelerated expansion of the Universe takes place at negative energy density, but with a positive pressure. It has also been possible to obtain the change of sign of the deceleration parameter q during cosmic evolution.

Citations

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Particle creation by black holes

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• Dynamical Dark Energy in the Crosshairs: A Joint Analysis with DESI, Pantheon plus, and TDCOSMO Constraints
• Hubble expansion and structure formation in the ``running FLRW model'' of the cosmic evolution
• Two Dynamical Scenarios for Binned Master Sample Interpretation. [europepmc]

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