Cosmological consequences of a scalar field with oscillating equation of state: A possible solution to the fine-tuning and coincidence problems [CEA]

http://arxiv.org/abs/1912.13208


We propose a new dark energy model for solving the cosmological fine-tuning and coincidence problems. The key idea is that the Universe may have several acceleration phases across the history. The specific example we study is a quintessence model with repeated approximately double exponential potential, which only introduces one Planck scale parameter and three dimensionless parameters of order unity. The cosmological background evolution equations can be recast into a four-dimensional dynamical system. The main properties of this system are discussed in details. As a bonus, our model provides a natural unification of early inflation, late-time dark energy and early dark energy recently proposed to ease the Hubble tension.

Read this paper on arXiv…

S. Tian
Wed, 1 Jan 20
69/88

Comments: 5 pages, 3 figures, submitted to PRD