Constraints for the thawing and freezing potentials
Year: 2017
Type: article
Abstract: We study the accelerating present universe in terms of the time evolution of the equation of state |$w(z)$| (redshift |$z$|) due to thawing and freezing scalar potentials in the quintessence model. The values of |$dw/da$| and |$d^2w/da^2$| at a scale factor of |$a = 1$| are associated with two parameters of each potential. For five types of scalar potentials, the scalar fields |$Q$| and |$w$| as functions of time |$t$| and/or |$z$| are numerically calculated under the fixed boundary condition of |$w(z=0)=-1+\Delta$|. The observational constraint |$w_{\rm obs}$| (Planck Collaboration, arXiv:1502.01590) is imposed to test whether the numerical |$w(z)$| is in |$w_{\rm obs}$|. Some solutions show thawing features in the freezing potentials. Mutually exclusive allowed regions in the |$dw/da$| vs. |$d^2w/da^2$| diagram are obtained in order to identify the likely scalar potential and even the potential parameters for future observational tests.
DOI: 10.1093/ptep/ptx160
Authors: Tetsuya Hara, Anna Suzuki, Shogo Saka, Takuma Tanigawa
Institution: Kyoto Sangyo University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $979
OpenAlex ID: W2735373704