The magnetic universe in the theory of gravity with non-minimal kinetic coupling of a scalar field
Abstract
In this paper, we obtain cosmological solutions within the framework of Bianchi I model with a unidirectional magnetic field in the theory of gravity with non-minimum kinetic coupling of a scalar field with curvature (η·(ϕ/2)· Gμν ∇μ∇νϕ). We believe that the solutions are applicable to the period before and during primary inflation. In the previous work [R. K. Muharlyamov, T. N. Pankratyeva, S. O. A. Bashir, JCAP05(2025)018] we considered such a problem for a special case -- the locally rotationally symmetric Bianchi I space-time (a1=a2). Here we generalize the results for different scale factors a1≠ a2 ≠ a3. There are distinctive properties of the models and a number of interesting properties are preserved. The main conclusion remains valid. For l=1+εηΛ/μ>0, the model has the necessary properties: isotropization during expansion, rapid transition to inflationary expansion, absence of ghost and Laplace instabilities. Here, Λ is the cosmological constant, μ=M2PL is the Planck mass squared, the sign ε=± 1 defines the canonical scalar field and the phantom field, respectively. The differences in the model appear in the neighborhood of the starting point and at times of several units hη· t from it (hη=√(ε/3η)). In the previous model with l>0, the Universe is described by the Kasner metric in the neighborhood of the initial point. In the generalized model, there is no the Kasner metric. In the presented model, the anisotropy level is a non-monotonic function. There is a rebound point on the plot. This is the non-standard behavior. But, in the end, the process of isotropization occurs.
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BibTeX
@misc{muharlyamov2026magnetic,
title = {{The magnetic universe in the theory of gravity with non-minimal kinetic coupling of a scalar field}},
author = {Ruslan K. Muharlyamov and Tatiana N. Pankratyeva},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.23739},
eprint = {2610.23739},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.23739},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The magnetic universe in the theory of gravity with non-minimal kinetic coupling of a scalar field
AU - Ruslan K. Muharlyamov
AU - Tatiana N. Pankratyeva
PY - 2026
DA - 2026/10/16
PB - arXiv
DO - 10.48550/arxiv.2610.23739
UR - https://arxiv.org/abs/2610.23739
AB - In this paper, we obtain cosmological solutions within the framework of Bianchi I model with a unidirectional magnetic field in the theory of gravity with non-minimum kinetic coupling of a scalar field with curvature (η·(ϕ/2)· G_μν ∇^μ∇^νϕ). We believe that the solutions are applicable to the period before and during primary inflation. In the previous work [R. K. Muharlyamov, T. N. Pankratyeva, S. O. A. Bashir, JCAP05(2025)018] we considered such a problem for a special case -- the locally rotationally symmetric Bianchi I space-time (a_1=a_2). Here we generalize the results for different scale factors a_1≠ a_2 ≠ a_3. There are distinctive properties of the models and a number of interesting properties are preserved. The main conclusion remains valid. For l=1+εηΛ/μ>0, the model has the necessary properties: isotropization during expansion, rapid transition to inflationary expansion, absence of ghost and Laplace instabilities. Here, Λ is the cosmological constant, μ=M^2_PL is the Planck mass squared, the sign ε=± 1 defines the canonical scalar field and the phantom field, respectively. The differences in the model appear in the neighborhood of the starting point and at times of several units h_η· t from it (h_η=√(ε/3η)). In the previous model with l>0, the Universe is described by the Kasner metric in the neighborhood of the initial point. In the generalized model, there is no the Kasner metric. In the presented model, the anisotropy level is a non-monotonic function. There is a rebound point on the plot. This is the non-standard behavior. But, in the end, the process of isotropization occurs.
ER -