f ( R ) gravity is a well-known modification of General Relativity, which is used in various models of dark matter and dynamical dark energy. We study static spherically symmetric (SSS) asymptotically flat configurations of the f ( R ) gravity in the Einstein frame for three known scalaron potentials with different asymptotic properties. The main attention is paid to the case of astrophysically relevant configuration mass M and scalaron mass μ greater than several meV , according to existing experimental constraints. This means very large values of the dimensionless (in geometrized units) parameter Mμ , leading to specific properties of the SSS solutions. We consider a sufficiently large size of a scalarization region r 0 ≫ r g , where the space-time metric is essentially different from the Schwarzschild one. It turns out that the scalaron field has universal behavior regardless of Mμ and r 0 and is practically the same for different scalaron potentials. Asymptotic parameters of the metric near the naked singularity at the center of the SSS configuration are obtained analytically for all the models. The test body circular orbits are discussed in view of observational signatures, which can distinguish these configurations from a regular black hole.

In this paper, we are testing the accretion dynamics of test fluids in the spacetime of a newly proposed black hole (BH) solution. We begin by presenting the BH metric and systematically examining its geometric and structural properties that are directly relevant for accretion processes. The exact analytical solutions for fluid accretion are derived, and their physical validity is carefully assessed. We perform a comprehensive dynamical system analysis, including the identification and classification of sonic points, and apply the formalism to isothermal fluids. The behavior of accretion flows is additionally examined through the Hamiltonian dynamical system approach across various fluid types, including ultra-stiff, ultra-relativistic, radiation, and sub-relativistic regimes. Under these conditions, the corresponding plots and phase-space representations illustrate the effects of BH parameters on the flow dynamics. The analysis is then extended to fluids following a polytropic EoS, and the physical implications of the mass accretion rate are thoroughly discussed. In addition, we perform general relativistic hydrodynamics (GRHD) simulations to validate the analytical predictions. The numerical results confirm the existence of steady transonic accretion, the formation of shock structures, and the sensitivity of the flow morphology and accretion efficiency to the non-commutative parameters. Overall, the simulations provide a consistent and self-contained description of fluid accretion in the proposed BH spacetime, with implications for both theoretical studies and astrophysical modeling.