Mimetic inflation

Mansoori, Seyed Ali Hosseini; Talebian, Alireza; Firouzjahi, Hassan

doi:10.1007/jhep01(2021)183

“…With appropriate choice of the potential, the generalized model can provide inflation, bounce, dark energy, and so on. This has stimulated extensive cosmological and astrophysical interests [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], and mimetic scenario has also been applied in various modified gravity theories [31][32][33][34][35][36][37][38][39][40][41][42][43][44]. The Hamiltonian analysis of different kinds of mimetic models were investigated in refs.…”

Section: Jhep04(2023)042mentioning

confidence: 99%

Extensions of two-field mimetic gravity

Zheng

¹

,

Rao

²

2023

J. High Energ. Phys.

1

0

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Two-field mimetic gravity was recently realized by looking at the singular limit of the conformal transformation between the auxiliary metric and the physical metric with two scalar fields involved. In this paper, we reanalyze the singular conformal limit and find a more general solution for the conformal factor A, which greatly broadens the form of two-field mimetic constraint and thus extends the two-field mimetic gravity. We find the general setup still mimics the role of dark matter at the cosmological background level. Moreover, we extend the action by introducing extra possible term for phenomenological interests. Surprisingly, some special cases are found to be equivalent to general relativity, k-essence theory and Galileon theory. Finally, we further extend the theory by allowing the expression of mimetic constraint to be arbitrary without imposed condition, and show that the dark matter-like behavior is unaffected even in this extension.

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“…It is worth to remark that the unification of the holographic dark energy and the holographic inflation has also been realised by various modified gravities 88 . Note that inflation for the mimetic gravity with its extensions, was also recently investigated 19 , 46 , 50 , 71 , 72 .…”

Section: Introductionmentioning

confidence: 95%

Cosmology in the mimetic higher-curvature $$f(R,R_{\mu \nu }R^{\mu \nu })$$ gravity

Kaczmarek

¹

,

Szczęśniak

²

2021

Sci Rep

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In the framework of the mimetic approach, we study the $$f(R,R_{\mu \nu }R^{\mu \nu })$$ f ( R , R μ ν R μ ν ) gravity with the Lagrange multiplier constraint and the scalar potential. We introduce field equations for the discussed theory and overview their properties. By using the general reconstruction scheme we obtain the power law cosmology model for the $$f(R,R_{\mu \nu }R^{\mu \nu })=R+d(R_{\mu \nu }R^{\mu \nu })^p$$ f ( R , R μ ν R μ ν ) = R + d ( R μ ν R μ ν ) p case as well as the model that describes symmetric bounce. Moreover, we reconstruct model, unifying both matter dominated and accelerated phases, where ordinary matter is neglected. Using inverted reconstruction scheme we recover specific $$f(R,R_{\mu \nu }R^{\mu \nu })$$ f ( R , R μ ν R μ ν ) function which give rise to the de-Sitter evolution. Finally, by employing the perfect fluid approach, we demonstrate that this model can realize inflation consistent with the bounds coming from the BICEP2/Keck array and the Planck data. We also discuss the holographic dark energy density in terms of the presented $$f(R,R_{\mu \nu }R^{\mu \nu })$$ f ( R , R μ ν R μ ν ) theory. Thus, it is suggested that the introduced extension of the mimetic regime may describe any given cosmological model.

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“…As a consequence, the conformal degree of freedom turns out to be dynamical, even in the absence of the standard matter fluids, and may mimic behavior of the cold dark matter. It is worth to remark here, that the mimetic theory has been recently extensively studied in various contexts [36,37,38,39,40,41,42,43,44]. Moreover, the mimetic approach has been combined with other modifications of gravity, such as f (R), f (G) or f (R, T ) theories with emphasis on the cosmological applications [45,46,47,48,49,50,51,52].…”

Section: Introductionmentioning

confidence: 99%

“…Alternatively, other modifications of the GR were studied in the context of inflation as well as the unification of accelerated phases of the Universe [5,66]. Note that inflation for the mimetic gravity with its extensions, was also recently investigated [19,43,47,67,68].…”

Section: Introductionmentioning

confidence: 99%

Cosmology in the mimetic higher-curvature $f(R, R_{μν}R^{μν})$ gravity

Kaczmarek,

Szczęśniak

2021

Preprint

0

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In the framework of the mimetic approach, we study the f (R, Rµν R µν ) gravity with the Lagrange multiplier constraint and the scalar potential. We introduce field equations for the discussed theory and overview their properties. By using the general reconstruction scheme we obtain the power law cosmology model for the f (R, Rµν R µν ) = R + d(Rµν R µν ) p case as well as the model that describes symmetric bounce. Moreover, we reconstruct model, unifying both matter dominated and accelerated phases, where ordinary matter is neglected. Using inverted reconstruction scheme we recover specific f (R, Rµν R µν ) function which give rise to the de-Sitter evolution. Finally, by employing the perfect fluid approach, we demonstrate that this model can realize inflation consistent with the bounds coming from the BICEP2/Keck array and the Planck data. Thus, it is suggested that the introduced extension of the mimetic regime may describe any given cosmological model.

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Mimetic inflation

Cited by 12 publications

References 85 publications

Extensions of two-field mimetic gravity

Extensions of two-field mimetic gravity

Cosmology in the mimetic higher-curvature $$f(R,R_{\mu \nu }R^{\mu \nu })$$ gravity

Cosmology in the mimetic higher-curvature $f(R, R_{μν}R^{μν})$ gravity

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