Vol. 24 No. 3 (2025): Mapana Journal of Sciences
Research Articles

An accelerating flat universe with an inverse square variation of the equation of state parameter with scale factor.

  • Sivakumar Chandrahasan,
  • Robin Francis
Sivakumar Chandrahasan
Maharaja's Collge affiliated to M G University, Kottayam
Robin Francis
Department of Physics, Maharaja’s College (affiliated to M G University, Kottayam), Ernakulam, Kochi-682011, Kerala, India

Published 2025-09-29

Keywords

  • Accelarating expansion,
  • Hubble parameter,
  • Pressure parameter,
  • Dark energy

Copyright (c) 2025

Creative Commons License

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Abstract

The pressure parameter in the equation of state (EoS) of the cosmic fluid that varies inversely as the square of the scale factor is a possibility to explain the evolution of our flat universe, presently expanding with an increasing acceleration under the negative pressure of a dynamic dark energy. The proposed model demonstrates the switch over from a state of decelerating expansion to a state of accelerating expansion of the universe using a simple equation of state consistent with the cosmological observations by introducing an effective pressure parameter in the equation of state for the cosmic fluid which comprises of radiation, matter and dark energy.

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