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Phenomenological equation of state and late-time cosmic acceleration

Golam Mortuza Hossain·Parthasarathi Majumdar
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Abstract

Assuming a flat Friedmann-Robertson-Walker cosmology with a single perfect fluid, we propose a pressure-density ratio that evolves as a specific universal function of the scale parameter. We show that such a ratio can indeed be consistent with several observational constraints including those pertaining to late-time accelerated expansion. Generic dynamical scalar field models of Dark energy (with quadratic kinetic terms in their Lagrange density) are shown to be in accord with the proposed equation-of-state ratio, provided the current matter density parameter $Ω_{m0} < 0.23$ - a value {\it not} in agreement with recent measurements.

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Golam Mortuza Hossain, Parthasarathi Majumdar. 2002-06-12. Phenomenological equation of state and late-time cosmic acceleration. https://arxiv.org/abs/gr-qc/0206026

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