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    Exploring the deviation of cosmological constant by a generalized pressure dark energy model

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    We bring forward a generalized pressure dark energy (GPDE) model to explore the evolution of the universe. This model has covered three common pressure parameterization types and can be reconstructed as quintessence and phantom scalar fields, respectively. We adopt the cosmic chronometer (CC) datasets to constrain the parameters. The results show that the inferred late-universe parameters of the GPDE model are (within 1Οƒ1\sigma): The present value of Hubble constant H0=(72.30βˆ’1.37+1.26)H_{0}=(72.30^{+1.26}_{-1.37})km sβˆ’1^{-1} Mpcβˆ’1^{-1}; Matter density parameter Ξ©m0=0.302βˆ’0.047+0.046\Omega_{\text{m0}}=0.302^{+0.046}_{-0.047}, and the universe bias towards quintessence. While when we combine CC data and the H0H_0 data from Planck, the constraint implies that our model matches the Ξ›\LambdaCDM model nicely. Then we perform dynamic analysis on the GPDE model and find that there is an attractor or a saddle point in the system corresponding to the different values of parameters. Finally, we discuss the ultimate fate of the universe under the phantom scenario in the GPDE model. It is demonstrated that three cases of pseudo rip, little rip, and big rip are all possible.Comment: 11 pages, 5 figures, 5 table
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