Viable intermediate inflation in the mimetic DBI model
Abstract We study the intermediate inflation in the mimetic Dirac–Born–Infeld model. By considering the scale factor as $$a=a_{0}\exp (bt^{\beta })$$ a = a 0 exp ( b t β ) , we show that in some ranges of the intermediate parameters b and $$\beta $$ β , the model is free of the ghost and gradient in...
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Online Access: | https://doi.org/10.1140/epjc/s10052-021-09619-2 |
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doaj-51f9e6975135489983e06af838d18ddb2021-09-26T11:16:30ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60441434-60522021-09-0181911410.1140/epjc/s10052-021-09619-2Viable intermediate inflation in the mimetic DBI modelNarges Rashidi0Kourosh Nozari1Department of Theoretical Physics, Faculty of Science, University of MazandaranDepartment of Theoretical Physics, Faculty of Science, University of MazandaranAbstract We study the intermediate inflation in the mimetic Dirac–Born–Infeld model. By considering the scale factor as $$a=a_{0}\exp (bt^{\beta })$$ a = a 0 exp ( b t β ) , we show that in some ranges of the intermediate parameters b and $$\beta $$ β , the model is free of the ghost and gradient instabilities. We study the scalar spectral index, tensor spectral index, and the tensor-to-scalar ratio in this model and compare the results with Planck2018 TT, TE, EE + lowE + lensing + BAO + BK14 data at 68% and 95% CL. In this regard, we find some constraints on the intermediate parameters that lead to the observationally viable values of the perturbation parameters. We also seek the non-Gaussian features of the primordial perturbations in the equilateral configuration. By performing the numerical analysis on the nonlinearity parameter in this configuration, we show that the amplitude of the non-Gaussianity in the intermediate mimetic DBI model is predicted to be in the range $$-16.7<f^{equil}<-12.5$$ - 16.7 < f equil < - 12.5 . We show that, with $$0<b\le 10$$ 0 < b ≤ 10 and $$0.345<\beta <0.387$$ 0.345 < β < 0.387 , we have an instabilities-free intermediate mimetic DBI model that gives the observationally viable perturbation and non-Gaussianity parameters.https://doi.org/10.1140/epjc/s10052-021-09619-2 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Narges Rashidi Kourosh Nozari |
spellingShingle |
Narges Rashidi Kourosh Nozari Viable intermediate inflation in the mimetic DBI model European Physical Journal C: Particles and Fields |
author_facet |
Narges Rashidi Kourosh Nozari |
author_sort |
Narges Rashidi |
title |
Viable intermediate inflation in the mimetic DBI model |
title_short |
Viable intermediate inflation in the mimetic DBI model |
title_full |
Viable intermediate inflation in the mimetic DBI model |
title_fullStr |
Viable intermediate inflation in the mimetic DBI model |
title_full_unstemmed |
Viable intermediate inflation in the mimetic DBI model |
title_sort |
viable intermediate inflation in the mimetic dbi model |
publisher |
SpringerOpen |
series |
European Physical Journal C: Particles and Fields |
issn |
1434-6044 1434-6052 |
publishDate |
2021-09-01 |
description |
Abstract We study the intermediate inflation in the mimetic Dirac–Born–Infeld model. By considering the scale factor as $$a=a_{0}\exp (bt^{\beta })$$ a = a 0 exp ( b t β ) , we show that in some ranges of the intermediate parameters b and $$\beta $$ β , the model is free of the ghost and gradient instabilities. We study the scalar spectral index, tensor spectral index, and the tensor-to-scalar ratio in this model and compare the results with Planck2018 TT, TE, EE + lowE + lensing + BAO + BK14 data at 68% and 95% CL. In this regard, we find some constraints on the intermediate parameters that lead to the observationally viable values of the perturbation parameters. We also seek the non-Gaussian features of the primordial perturbations in the equilateral configuration. By performing the numerical analysis on the nonlinearity parameter in this configuration, we show that the amplitude of the non-Gaussianity in the intermediate mimetic DBI model is predicted to be in the range $$-16.7<f^{equil}<-12.5$$ - 16.7 < f equil < - 12.5 . We show that, with $$0<b\le 10$$ 0 < b ≤ 10 and $$0.345<\beta <0.387$$ 0.345 < β < 0.387 , we have an instabilities-free intermediate mimetic DBI model that gives the observationally viable perturbation and non-Gaussianity parameters. |
url |
https://doi.org/10.1140/epjc/s10052-021-09619-2 |
work_keys_str_mv |
AT nargesrashidi viableintermediateinflationinthemimeticdbimodel AT kouroshnozari viableintermediateinflationinthemimeticdbimodel |
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1716868085772713984 |