English

Cylindrical black hole solutions in $f(\mathcal{R})$ and $f(\mathcal{R},\mathcal{A},A^{\mu\nu}A_{\mu\nu})$ modified gravity

General Relativity and Quantum Cosmology 2025-03-13 v2

Abstract

We explore a cylindrical black hole (BH) space-time introduced by Lemos, in the context of modified gravity theories. Specifically, we focus on f(R)f(\mathcal{R})-gravity framework, where we choose two form functions, f(R)=(R+α1R2+α2R3+α3R4+α4R5)f(\mathcal{R})=(\mathcal{R}+\alpha_1\,\mathcal{R}^2+\alpha_2\,\mathcal{R}^3+\alpha_3\,\mathcal{R}^4+\alpha_4\,\mathcal{R}^5) and f(R)=R+αkRk+1,(k=1,2,...n)f(\mathcal{R})=\mathcal{R}+\alpha_k\,\mathcal{R}^{k+1},\quad (k=1,2,...n). We solve the modified field equations incorporating zero energy-momentum tensor, Tμν=0\mathcal{T}^{\mu\nu}=0 and obtain the result. Moreover, we study another well-known modified gravity theory called Ricci-Inverse (RI\mathcal{RI}) gravity and investigate this Lemos black hole (LBH) space-time. To achieve this, we consider different classes of models defined as follows: (i) Class-\textbf{I} model: f(R,A)=(R+βA)f(\mathcal{R}, \mathcal{A})=(\mathcal{R}+\beta\,\mathcal{A}), (ii) Class-\textbf{II} model: f(R,AμνAμν)=(R+γAμνAμν)f(\mathcal{R}, A^{\mu\nu}\,A_{\mu\nu})=(\mathcal{R}+\gamma\,A^{\mu\nu}\,A_{\mu\nu}), and (iii) Class-\textbf{III} model: f(R,A,AμνAμν)=(R+α1R2+α2R3+β1A+β2A2+γAμνAμν)f(\mathcal{R}, \mathcal{A}, A^{\mu\nu}\,A_{\mu\nu})=(\mathcal{R}+\alpha_1\,\mathcal{R}^2+\alpha_2\,\mathcal{R}^3+\beta_1\,\mathcal{A}+\beta_2\,\mathcal{A}^2+\gamma\,A^{\mu\nu}\,A_{\mu\nu}), where A=gμνAμν\mathcal{A}=g_{\mu\nu}\,A^{\mu\nu} is the anti-curvature scalar, AμνA^{\mu\nu} is the anti-curvature tensor, the reciprocal of the Ricci tensor RμνR_{\mu\nu}. We solve the modified field equations under the same aforementioned scenario of energy-momentum tensor, and obtain the result. Subsequently, we study the geodesic motions of test particles around this LBH within the Ricci-Inverse and f(R)f(\mathcal{R})-gravity theories and analyze the outcomes. We demonstrate that different coupling constants chosen in these modified gravity theories influences the usual cosmological constant Λ\Lambda, and thus, shifted the result in comparison to the general relativity case.

Keywords

Cite

@article{arxiv.2411.00896,
  title  = {Cylindrical black hole solutions in $f(\mathcal{R})$ and $f(\mathcal{R},\mathcal{A},A^{\mu\nu}A_{\mu\nu})$ modified gravity},
  author = {Faizuddin Ahmed and Abdelmalek Bouzenada},
  journal= {arXiv preprint arXiv:2411.00896},
  year   = {2025}
}

Comments

28 pages, 7 figures, 1 table, accepted in Physics of the Dark Universe (https://doi.org/10.1016/j.dark.2025.101883), mathematics overlap with arXiv:2407.11513, arXiv:2410.11922