Exploring the deviation of cosmological constant by a generalized pressure parameterization

Abstract

Abstract We bring forward a generalized pressure (GP) parameterization for dark energy to explore the evolution of the universe. This parametric 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 GP parameterization are (within $$1\sigma $$1σ): the present value of Hubble constant $$H_{0}=(72.30^{+1.26}_{-1.37}) \ \hbox {km s}^{-1}\hbox { Mpc}^{-1}$$H0=(72.30-1.37+1.26)kms-1Mpc-1; the matter density parameter $$\Omega _{\text {m0}}=0.302^{+0.046}_{-0.047}$$Ωm0=0.302-0.047+0.046, and the bias of the universe towards quintessence. Then we perform a dynamic analysis on the GP parameterization and find that there is an attractor or a saddle point in the system corresponding to the different values of the parameters. Finally, we discuss the ultimate fate of the universe under the phantom scenario in the GP parameterization. It is demonstrated that the three cases of pseudo rip, little rip, and big rip are all possible.