In the context of f (R, T) theory, we address the viscous ghost dark energy model for a homogeneous and isotropic flat universe. To talk about the universe′s evolution, we derive the Hubble, deceleration, and effective equation of state parameters. We analyze the computed cosmological parameters in light of the model parameters′ best fit values and limit the model parameters using the most recent cosmological observations. The deceleration parameter shows a smooth phase transition of the universe from decelerated to accelerated expansion. The universe remains in accelerating phase in future also which shows that dark energy will dominate the universe in future as well. We observe that effective equation of state in our model never cross the phantom divide line and approaches to ΛCDM model in the future. We observe current values of the Hubble parameter <InlineEquation ID="IEq1"> <EquationSource Format="TEX">${H}_{0}={66.567}_{-1.048}^{+1.151}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>H</mi> <mn>0</mn> </msub> <mo>=</mo> <msubsup> <mrow> <mn>66.567</mn> </mrow> <mrow> <mo>-</mo> <mn>1.048</mn> </mrow> <mrow> <mo>+</mo> <mn>1.151</mn> </mrow> </msubsup> </mrow> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq2"> <EquationSource Format="TEX">${H}_{0}={69.582}_{-0.813}^{+0.905}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>H</mi> <mn>0</mn> </msub> <mo>=</mo> <msubsup> <mrow> <mn>69.582</mn> </mrow> <mrow> <mo>-</mo> <mn>0.813</mn> </mrow> <mrow> <mo>+</mo> <mn>0.905</mn> </mrow> </msubsup> </mrow> </math></EquationSource> </InlineEquation> for SNIa+OHD+SLS and SNIa+OHD+SH0ES, respectively. The estimated current ages of the universe are 15. 13 Gyr for SNIa+OHD+SLS and 15. 61 Gyr for the SNIa+OHD+SH0ES. We observe that the present model is able to resolve H0 tension and age problem of the standard ΛCDM model. Further, we apply higher order geometric analysis namely statefinder jerk, snap, and lerk parameters to discriminate our model with existing DE models. The trajectories in r - s and r - q planes pass through ΛCDM model during the evolution but the overall evolution of the trajectories differs from any known dark energy model.

Observational Constraining of Viscous Ghost Dark Energy in f(R,T) Gravity

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发表日期：

2025年9月1日

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Pinki,
K. Devi,
A. Kumar,
P. Kumar

摘要

In the context of f (R, T) theory, we address the viscous ghost dark energy model for a homogeneous and isotropic flat universe. To talk about the universe′s evolution, we derive the Hubble, deceleration, and effective equation of state parameters. We analyze the computed cosmological parameters in light of the model parameters′ best fit values and limit the model parameters using the most recent cosmological observations. The deceleration parameter shows a smooth phase transition of the universe from decelerated to accelerated expansion. The universe remains in accelerating phase in future also which shows that dark energy will dominate the universe in future as well. We observe that effective equation of state in our model never cross the phantom divide line and approaches to ΛCDM model in the future. We observe current values of the Hubble parameter ${H}_{0}={66.567}_{-1.048}^{+1.151}$ $H_{0} = {66.567}_{- 1.048}^{+ 1.151}$ and ${H}_{0}={69.582}_{-0.813}^{+0.905}$ $H_{0} = {69.582}_{- 0.813}^{+ 0.905}$ for SNIa+OHD+SLS and SNIa+OHD+SH0ES, respectively. The estimated current ages of the universe are 15. 13 Gyr for SNIa+OHD+SLS and 15. 61 Gyr for the SNIa+OHD+SH0ES. We observe that the present model is able to resolve H0 tension and age problem of the standard ΛCDM model. Further, we apply higher order geometric analysis namely statefinder jerk, snap, and lerk parameters to discriminate our model with existing DE models. The trajectories in r - s and r - q planes pass through ΛCDM model during the evolution but the overall evolution of the trajectories differs from any known dark energy model.