Theoretical physics

Cosmology

Big Rip

Astrophysics

Scalar field dark matter

Scalar field

Classical mechanics

Metric expansion of space

Dark energy

Physics

Mathematics

Attractor

Mathematical analysis

Quintessence

De Sitter universe

Dark matter

Dark fluid

Universe

Lambda-CDM model

Journal of Cosmology and Astroparticle Physics

We present a detailed investigation of the dynamical behavior of mimetic gravity with a general potential for the mimetic scalar field. Performing a phase-space and stability analysis, we show that the scenario at hand can successfully describe the thermal history of the universe, namely the successive sequence of radiation, matter, and dark-energy eras. Additionally, at late times the universe can either approach a de Sitter solution, or a scaling accelerated attractor where the dark-matter and dark-energy density parameters are of the same order, thus offering an alleviation of the cosmic coincidence problem. Applying our general analysis to various specific potential choices, including the power-law and the exponential ones, we show that mimetic gravity can be brought into good agreement with the observed behavior of the universe. Moreover, with an inverse square potential we find that mimetic gravity offers an appealing unified cosmological scenario where both dark energy and dark matter are characterized by a single scalar field, and where the cosmic coincidence problem is alleviated.

Cosmological dynamics of mimetic gravity