2024/02/06 by Haximjan Abdusattar, Abdusattar, Haximjan, Shi‐Bei Kong +1
Earth and Planetary Sciences · Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Physics - Theory (hep-th)
paper · pdf · doi:10.48550/arxiv.2402.03733
openalex publication_date 2024/02/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, within the framework of modified gravity involving a conformal scalar field, we investigate the Joule-Thomson expansion of the FRW universe to identify cooling and heating regions. Notably, we observe that the Joule-Thomson coefficient, denoted as μ, diverges at RA=√(-2α) when α<0, aligning with the thermodynamic singularity of the FRW universe. Additionally, we determine the inversion temperature and inversion pressure for the FRW universe, and illustrate the characteristics of inversion curves and isenthalpic curves in the T-P plane. We compare these findings with results obtained under Einstein gravity, discussing the influence of the modification term on the cooling and heating properties of the FRW universe. This work contributes significantly to a deeper understanding of the formation of cooling and heating regions within the FRW universe, thereby advancing our comprehension of the physical mechanisms that govern the expansion of our universe.