Turkish Journal of Physics
Abstract
We derive several equations of state for different types of energy from the first law of thermodynamics. We derive the equation of state of a Machian universe from the well-known energy formulaE=mc2. This equation of state is consistent with previously reported results. We then propose hypothetical forms of energy that lead to the equations of state of the Chaplygin gas, generalized Chaplygin gas, and modified Chaplygin gas. We also obtain the energy density of the Chaplygin gas by dividing the hypothetical energy by the volume of the universe, and find that it is consistent with previously reported results. Finally, we consider a toy model of energy.
Author ORCID Identifier
CH'NG SIONG: 0000-0002-0915-1310
DOI
10.55730/1300-0101.2820
Keywords
Equation of state, Chaplygin gas, energy density, Chaplygin energy
First Page
283
Last Page
291
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
SIONG, C. H (2026). On cosmological equation of state from the first law of thermodynamics. Turkish Journal of Physics 50 (4): 283-291. https://doi.org/10.55730/1300-0101.2820
