Thawing kessence dark energy in the PAge space
Abstract
A broad class of dark energy models can be written in the form of kessence, whose Lagrangian density is a twovariable function of a scalar field ϕ and its kinetic energy $X\equiv \tfrac{1}{2}{\partial }^{\mu }\phi {\partial }_{\mu }\phi $ . In the thawing scenario, the scalar field becomes dynamic only when the Hubble friction drops below its mass scale in the late Universe. Thawing kessence dark energy models can be randomly sampled by generating the Taylor expansion coefficients of its Lagrangian density from random matrices [Huang Z 2021 Phys. Rev. D 104 103533]. Reference [Huang Z 2021 Phys. Rev. D 104 103533] points out that the nonuniform distribution of the effective equation of state parameters (w _{0}, w _{ a }) of the thawing kessence model can be used to improve the statistics of model selection. The present work studies the statistics of thawing kessence in a more general framework that is Parameterized by the Age of the Universe (PAge) [Huang Z 2020 Astrophys. J. Lett. 892 L28]. For fixed matter fraction Ω_{ m }, the random thawing kessence models cluster in a narrow band in the PAge parameter space, providing a strong theoretical prior. We simulate cosmic shear power spectrum data for the Chinese Space Station Telescope optical survey, and compare the fisher forecast with and without the theoretical prior of thawing kessence. For an optimal tomography binning scheme, the theoretical prior improves the figure of merit in PAge space by a factor of 3.3.
 Publication:

Communications in Theoretical Physics
 Pub Date:
 September 2022
 DOI:
 10.1088/15729494/ac80ed
 arXiv:
 arXiv:2204.09713
 Bibcode:
 2022CoTPh..74i5404H
 Keywords:

 dark energy;
 cosmological parameters;
 largescale structure of universe;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory;
 83F05;
 J.2
 EPrint:
 24 pages, 5 figures, submission invited by Commun. Theor. Phys