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Title: Instabilities in mimetic matter perturbations

Abstract

We study cosmological perturbations in mimetic matter scenario with a general higher derivative function. We calculate the quadratic action and show that both the kinetic term and the gradient term have the wrong sings. We perform the analysis in both comoving and Newtonian gauges and confirm that the Hamiltonians and the associated instabilities are consistent with each other in both gauges. The existence of instabilities is independent of the specific form of higher derivative function which generates gradients for mimetic field perturbations. It is verified that the ghost instability in mimetic perturbations is not associated with the higher derivative instabilities such as the Ostrogradsky ghost.

Authors:
;  [1];  [2]
  1. School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)
  2. Physics Department, Shahrood University of Technology, P.O. Box 3619995161 Shahrood (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
22676097
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 07; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTERIZED SIMULATION; COSMOLOGICAL MODELS; DISTURBANCES; HAMILTONIANS; INSTABILITY; PERTURBATION THEORY

Citation Formats

Firouzjahi, Hassan, Gorji, Mohammad Ali, and Mansoori, Seyed Ali Hosseini, E-mail: firouz@ipm.ir, E-mail: gorji@ipm.ir, E-mail: shosseini@shahroodut.ac.ir, E-mail: shossein@ipm.ir. Instabilities in mimetic matter perturbations. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/07/031.
Firouzjahi, Hassan, Gorji, Mohammad Ali, & Mansoori, Seyed Ali Hosseini, E-mail: firouz@ipm.ir, E-mail: gorji@ipm.ir, E-mail: shosseini@shahroodut.ac.ir, E-mail: shossein@ipm.ir. Instabilities in mimetic matter perturbations. United States. doi:10.1088/1475-7516/2017/07/031.
Firouzjahi, Hassan, Gorji, Mohammad Ali, and Mansoori, Seyed Ali Hosseini, E-mail: firouz@ipm.ir, E-mail: gorji@ipm.ir, E-mail: shosseini@shahroodut.ac.ir, E-mail: shossein@ipm.ir. Sat . "Instabilities in mimetic matter perturbations". United States. doi:10.1088/1475-7516/2017/07/031.
@article{osti_22676097,
title = {Instabilities in mimetic matter perturbations},
author = {Firouzjahi, Hassan and Gorji, Mohammad Ali and Mansoori, Seyed Ali Hosseini, E-mail: firouz@ipm.ir, E-mail: gorji@ipm.ir, E-mail: shosseini@shahroodut.ac.ir, E-mail: shossein@ipm.ir},
abstractNote = {We study cosmological perturbations in mimetic matter scenario with a general higher derivative function. We calculate the quadratic action and show that both the kinetic term and the gradient term have the wrong sings. We perform the analysis in both comoving and Newtonian gauges and confirm that the Hamiltonians and the associated instabilities are consistent with each other in both gauges. The existence of instabilities is independent of the specific form of higher derivative function which generates gradients for mimetic field perturbations. It is verified that the ghost instability in mimetic perturbations is not associated with the higher derivative instabilities such as the Ostrogradsky ghost.},
doi = {10.1088/1475-7516/2017/07/031},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 07,
volume = 2017,
place = {United States},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}