# Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

@article{Hirano2017HealthyID, title={Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations}, author={Shin'ichi Hirano and Sakine Nishi and Tsutomu Kobayashi}, journal={Journal of Cosmology and Astroparticle Physics}, year={2017}, volume={2017}, pages={009 - 009} }

We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of…

## 43 Citations

### Reconstruction of Mimetic Gravity in a Non-Singular Bouncing Universe from Quantum Gravity

- PhysicsUniverse
- 2019

We illustrate a general reconstruction procedure for mimetic gravity. Focusing on a bouncing cosmological background, we derive general properties that must be satisfied by the function f(□ϕ)…

### Direct couplings of mimetic dark matter and their cosmological effects

- Physics
- 2017

The original mimetic model was proposed to take the role of dark matter. In this paper we consider possible direct interactions of the mimetic dark matter with other matter in the universe,…

### Mimicking dark matter and dark energy in a mimetic model compatible with GW170817

- PhysicsPhysics of the Dark Universe
- 2018

### Extended mimetic gravity: Hamiltonian analysis and gradient instabilities

- PhysicsThe Fifteenth Marcel Grossmann Meeting
- 2022

We propose a novel class of degenerate higher-order scalar-tensor theories as an extension of mimetic gravity. By performing a noninvertible conformal transformation on “seed” scalar-tensor theories…

### Towards a viable effective field theory of mimetic gravity

- PhysicsJournal of Cosmology and Astroparticle Physics
- 2019

We discuss mimetic gravity theories with direct couplings between the curvature and higher derivatives of the scalar field, up to the quintic order, which were proposed to solve the instability…

### Cosmological dynamics of mimetic gravity

- Physics
- 2017

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…

### Limiting curvature mimetic gravity and its relation to Loop Quantum Cosmology

- PhysicsGeneral Relativity and Gravitation
- 2019

Considering as usual that the underlying geometry of our universe is well described by the spatially flat Friedmann–Lemaître–Robertson–Walker line element, we review how the background of holonomy…

### Higher derivative mimetic gravity

- Physics
- 2017

We study cosmological perturbations in mimetic gravity in the presence of classified higher derivative terms which can make the mimetic perturbations stable. We show that the quadratic higher…

### Cosmology in mimetic SU(2) gauge theory

- PhysicsJournal of Cosmology and Astroparticle Physics
- 2019

It is well known that the standard scalar field mimetic cosmology provides a dark matter-like energy density component. Considering SU(2) gauge symmetry, we study the gauge field extension of the…

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