arXiv subjects

Anto Sulaksono

Publications and source records attributed to Anto Sulaksono.

6 recordsLinked to original sources

arXiv2026

Renormalization group improved black holes in non-commutative momentum-dependent spacetime geometry

We investigate black holes (BHs) in momentum-dependent spacetime geometry and assess its quantum Reissner-Nordstr\"om (RN) consistency with the weak gravity conjecture (WGC). Quantum corrections are introduced through the non-commutative momentum space algebra as the quantization process, and spacetime renormalization approach as a map between momentum and spacetime spaces. For the Schwarzschild case, thermodynamic analysis indicates the existence of a hot (non-zero temperature) BH remnant when evaporation stops (the entropy becomes zero), obeying a complementary third law for black hole thermodynamics. We extend this framework to the RN solution and examine its extremal limit. For large BHs with $M \gg M_P$ ($M_P$ for Planck mass), the quantum-improved RN geometry exhibits a non-zero Hawking temperature in the extremal case, consistent with the WGC, which stipulates that extremal states should not be exactly stable or cold. The resulting momentum-dependent metric and thermodynamic properties are shown to reproduce the results derived from the Poincar\'e algebra (classical model) in the infrared (IR) regime.

gr-qc↗

arXiv2025

The Milky Way and M31 rotation curves in Yukawa gravity: phenomenology and Bayesian analysis

Yukawa gravity provides a generalized framework for modeling gravity modification. We investigate the rotation curve profiles of spiral galaxies under Yukawa-like theories governed by the coupling strength $β$ and the interaction range $λ$. We develop a unified analytical and numerical framework to calculate rotational velocities under Yukawa gravity, which includes contributions from all major galactic components: stellar bulge, disk, dark matter (DM) halo, and central supermassive black hole. The calculations show that $β$ and $λ$ strongly influence velocity distributions, shifting peaks, creating double-peak structures, or enhancing dark matter dominance in the bulge or disk. To assess observational implications, we perform Bayesian analyses using data from the Milky Way (MW) and Andromeda (M31), which offer complementary characteristics: MW provides precise velocity profiles across multiple scales, while M31 includes broader morphological constraints. We examine four scenarios: Yukawa gravity without dark matter, dark matter with non-trivial coupling, fully modified gravity, and standard Newtonian gravity. Results show that MW models with $λ< 1$ kpc yield high Bayes factors but risk overfitting, as dark matter mimics baryonic kinematics, while M31's photometric priors from conjugate observations mitigate this, yielding robust parameter estimates. However, in M31, Bayes factors favor Newtonian gravity, suggesting that current data lack the precision to resolve more complex models. This finding highlights two key needs: (i) realistic, physically or empirically informed priors to avoid biased constraints, and (ii) high-precision data with independent photometry to guard against overfitting. Our framework offers a scalable approach for testing gravity with large galactic rotation curve datasets.

astro-ph.GA↗

arXiv2022

Rotating black holes and exotic compact objects in the Kerr/CFT correspondence within Rastall gravity

Quantum gravitational effects on the near horizon may alter the black hole's horizon drastically to be partially reflective, portrayed by a quantum membrane. With this modification, the object can be considered as an exotic compact object (ECO). Quantum effects on the strong gravitational regime may also lead to a non-conserved matter tensor that can be described phenomenologically using Rastall gravity. In this work, we study the properties of black holes and ECOs within Rastall gravity using Kerr/CFT correspondence. We systematically investigate the properties of the most general rotating black hole solutions in Rastall gravity, i.e., Kerr-Newman-NUT-Kiselev, and reveal its hidden conformal symmetry. The Cardy microscopic entropy formula and absorption cross-sections from 2D CFT are computed and then matched with gravity calculation. We also extend the dual CFT analysis for studying the properties of ECOs. The existence of the quantum membrane leads to the appearance of the gravitational echoes that is manifested as an oscillatory feature on the absorption cross-section. We compute the absorption cross-section and quasi-normal modes in the dual CFT picture. We also compare the absorption cross-section of ECOs to that of black holes. We find that the Rastall coupling constant plays a significant role for both objects. We also obtain that the echo time delay depends explicitly on the Rastall coupling constant. This coupling constant may play a role to recover the correction on time delay that is believed as a non-linear physics effect. Henceforth, the signature of the Rastall gravity can be probed from the time-delay observation.

hep-th↗

arXiv2021

Testing Short Distance Anisotropy in Space

The isotropy of space is not a logical requirement but rather is an empirical question; indeed there is suggestive evidence that universe might be anisotropic. A plausible source of these anisotropies could be quantum gravity corrections. If these corrections happen to be between the electroweak scale and the Planck scale, then these anisotropies can have measurable consequences at short distances and their effects can be measured using ultra sensitive condensed matter systems. We investigate how such anisotropic quantum gravity corrections modify low energy physics through an anisotropic deformation of the Heisenberg algebra. We discuss how such anisotropies might be observed using a scanning tunneling microscope.

gr-qc↗

arXiv2021

White dwarfs and generalized uncertainty principle

This work is motivated by the sign problem in a logarithmic parameter of black hole entropy and the existing more massive white dwarfs than the Chandrasekhar mass limit. We examine the quadratic, linear, and linear-quadratic generalized uncertainty principle (GUP) models within the virtue of recent masses and radii of white dwarfs. We consider the modification generated by introducing the minimal length proposal on the degenerate Fermi gas equation of state (EOS) and on the hydrostatic equation. For the latter, we applied Verlinde's proposal regarding entropic gravity to derived the quantum corrected Newtonian gravity which in turn responsible for modifying the hydrostatic equation. Through the chi-square analysis of the models, we have found that the observation data favor the quadratic dan linear GUP models without mass limit. However, for the quadratic-linear GUP model, we can obtain the positive value of the free parameter $γ_0$ as well as we can get mass limit more massive than the Chandrasekhar mass limit. In the linear-quadratic GUP model, the formation of stable massive white dwarfs than the Chandrasekhar limit is possible only if both parameters are not equal.

gr-qc↗

arXiv2021

Dark Energy Stars with Phantom Field

Dark energy is the constituent with an enormous abundance of the present universe, responsible for the universe's accelerated expansion. Therefore, it is plausible that dark energy may interact within any compact astrophysical objects. The author in Ref. [Phys. Rev. D 83, 127501 (2011)], constructs an exact star solution consisting of an ordinary matter and phantom field from a constant density star (CDS) known as Schwarzschild interior solution. The star denotes a dark energy star (DES). The author claims that the phantom field represents dark energy within the star. So far, the role of the phantom field as dark energy in DES is not systematically studied yet. Related to this issue, we analyze the energy condition of DES. We expect that DES shall violate the strong energy condition (SEC) for a particular condition. We discover that SEC is fully violated only when the compactness reaches the Buchdahl limit. Furthermore, we also investigate the causal conditions and stabilities due to the convective motion and gravitational cracking. We also find that those conditions are violated. These results indicate that DES is not physically stable. However, we may consider DES as an ultra-compact object of which we can calculate the gravitational wave echo time and echo frequency and compare them to those of CDS. We find that the contribution of the phantom field delays the gravitational wave echoes. The effective potential of the perturbed DES is also studied. The potential also enjoys a potential well like CDS but with a deeper well. We also investigate the possibility that DES could form a gravastar when $ C=1 $. It is found that gravastar produced from DES possesses no singularity with a dS-like phase as the interior. These results could open more opportunities for the observational study of dark energy in the near future, mostly from the compact astrophysical objects.

gr-qc↗