Thin Accretion Disk and Optical Signatures in f(R,T) Modified Gravity
Abstract
Accretion disk surrounding around compact astrophysical objects serve as a powerful laboratories for testing gravitational theories in the strong-field regimes. In this work, we systematically investigated the structural, dynamical, and thermodynamic properties of the steady-state thin accretion disk within the framework of f(R,T) gravity by adopting the linear functional form f(R,T) = R + 2χT coupled with the pressure-free dust fluid matter Lagrangian (ℒm = −ρ). We demonstrate that the modified field equations seamlessly reduce to standard General Relativity in the pure vacuum limit (Tμν = 0). Utilizing a perturbative approach for a small coupling parameter (|χ| ≪ 1), we derive the first-order corrections to the background Schwarzschild metric potentials, which subsequently govern the modified particle kinematics, the specific energy E, the specific angular momentum L, and the Keplerian angular velocity Ω. Our analysis reveals that the geometry-matter coupling parameter χ significantly shifted towards the location of the Innermost Stable Circular Orbit (risco) and alters the radial energy dissipation rate F(r) and the effective surface temperature profile T(r) across the Shakura-Sunyaev thin disk. Furthermore, the resulting modifications in the Spectral Energy Distribution (SED) and overall radiative efficiency η provide robust theoretical signature.
Related
- Optical Appearance of the Konoplya–Zhidenko Rotating Non‐Kerr Black Hole Surrounded by a Thin Accretion Disk
- Observational signatures of thin accretion disks around rotating black holes embedded in dark matter halos
- Thin accretion-disc transfer functions in the q-metric spacetime: quadrupolar lensing signatures
- Signatures of Novikov-Thorne accretion disks around rotating black holes in semiclassical gravity with trace anomaly
- Additional Observational Signatures of Asymmetric Thin-Shell Wormholes within 4D Einstein-Gauss-Bonnet Gravity
BibTeX
@misc{shekh2026thin,
title = {{Thin Accretion Disk and Optical Signatures in f(R,T) Modified Gravity}},
author = {S. H. Shekh},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.30319},
eprint = {2609.30319},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.30319},
}
RIS
TY - UNPB
TI - Thin Accretion Disk and Optical Signatures in f(R,T) Modified Gravity
AU - S. H. Shekh
PY - 2026
DA - 2026/09/23
PB - arXiv
DO - 10.48550/arxiv.2609.30319
UR - https://arxiv.org/abs/2609.30319
AB - Accretion disk surrounding around compact astrophysical objects serve as a powerful laboratories for testing gravitational theories in the strong-field regimes. In this work, we systematically investigated the structural, dynamical, and thermodynamic properties of the steady-state thin accretion disk within the framework of f(R,T) gravity by adopting the linear functional form f(R,T) = R + 2χT coupled with the pressure-free dust fluid matter Lagrangian (ℒ_m = −ρ). We demonstrate that the modified field equations seamlessly reduce to standard General Relativity in the pure vacuum limit (T_μν = 0). Utilizing a perturbative approach for a small coupling parameter (|χ| ≪ 1), we derive the first-order corrections to the background Schwarzschild metric potentials, which subsequently govern the modified particle kinematics, the specific energy E, the specific angular momentum L, and the Keplerian angular velocity Ω. Our analysis reveals that the geometry-matter coupling parameter χ significantly shifted towards the location of the Innermost Stable Circular Orbit (r_isco) and alters the radial energy dissipation rate F(r) and the effective surface temperature profile T(r) across the Shakura-Sunyaev thin disk. Furthermore, the resulting modifications in the Spectral Energy Distribution (SED) and overall radiative efficiency η provide robust theoretical signature.
ER -