| | |
| | |
Stat |
Members: 3643 Articles: 2'488'730 Articles rated: 2609
29 March 2024 |
|
| | | |
|
Article overview
| |
|
Scalar perturbations in $f(T)$ gravity using the $1+3$ covariant approach | Shambel Sahlu
; Joseph Ntahompagaze
; Amare Abebe
; Alvaro de la Cruz-Dombriz
; David F. Mota
; | Date: |
8 Jul 2019 | Abstract: | We investigate the cosmological scalar perturbations of standard matter in
the context of extended teleparallel $f(T)$ gravity theories using the 1 + 3
covariant formalism. We review the gravitational field equations of $f(T)$
gravity to introduce therein a gauge-invariant spatial gradient of the torsion
fluid and obtain the linear perturbation equations. After performing the usual
scalar and harmonic decompositions, we analyze the matter perturbations in the
quasi-static approximation for two non-interacting fluids scenarios, namely
torsion-dust and mixtures. We consider the $f(T)$ power-law paradigmatic
classes of model $f(T) = alpha(-T/T_0)^n$, for both torsion-dust and
torsion-radiation scenarios. Under this scope, exact solutions of the matter
perturbations are obtained. We examine the growth of the matter density
contrast for these mixtures. In a similar manner, we also consider the long-
and short-wavelength modes in the torsion-radiation case. We consider different
values of n to explore the growth of matter density contrast with red-shift.
For the case of n closer to one, our paradigmatic $f(T)$ gravity model is
favored with the usual results of general relativity (GR) and general
relativity with a cosmological constant ({Lambda}CDM). However, for the case
of ngg1 the amplitude of the matter density fluctuation extremely high and
unrealistic to compare with GR and {Lambda}CDM results for these
non-interacting fluids. Notably, in the torsion-radiation system, the behavior
of the growth of matter density contrasts is abandoned and ruled-out for n ll
1 in both wave modes. While our results show a richer set of possibilities that
can help to constrain the model parameters using future observational data,
they also accommodate currently known features of power spectrum in the
large-scale structure in the general relativistic limit. | Source: | arXiv, 1907.3563 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser claudebot
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |