Pith. sign in

REVIEW 6 cited by

Constraining a modified gravity theory in strong gravitational lensing and black hole shadow observations

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2206.05878 v2 pith:DDS2YWPE submitted 2022-06-13 gr-qc

classification gr-qc
keywords blackholesrotatinglensinggravityholelesssimshadow
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
abstract

We study the strong gravitational lensing effect around rotating black holes in different gravity theories. By calculating the deflection angle of strong gravitational lensing, we evaluate the lensing observables including the image position, separation, magnification and the time delays between the relativistic images of different rotating black holes. We argue that the differences in image positions, separations between the rotating black hole in modified gravity (MOG) theory and the Kerr black hole in general relativity (GR) are more significant in SgrA* than those in M87*, however the differences in time delays between rotating black holes in MOG and GR are shorter in SgrA* than that in M87*. Our evaluations on lensing observables in the strong gravity regime can help to distinguish the MOG from GR. Furthermore, we investigate the shadow observables of different rotating black holes. Employing the EHT observations on the angular shadow radius for supermassive M87* and SgrA* black holes respectively, we estimate the ranges of MOG parameter and obtain its upper limit constraint $0.350\lesssim\alpha_{\rm up}\lesssim 0.485$ and $0.162 \lesssim \alpha_{\rm up} \lesssim 0.285$ correspondingly, relating to black hole spins. This is the first constraint on the MOG parameter for rotating supermassive black holes from EHT observations on the angular shadow radius. Our constraint on the MOG parameter is much tighter compared with the result obtained from the orbital precession of the S2 star.

Discussion (0). Sign in to comment.

Forward citations

Cited by 6 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Critical Behavior of Photon Rings in Kerr-Bertotti-Robinson Spacetime

    gr-qc 2026-03 conditional novelty 6.0 of 10

    For a magnetized Kerr-Bertotti-Robinson black hole, the photon-ring parameters gamma, delta, and tau all decrease compared with the unmagnetized Kerr case, weakening the self-similar stacking of higher-order images.

  2. Optical Characteristics of the Kerr-Bertotti-Robinson Black Hole

    gr-qc 2025-08 conditional novelty 6.0 of 10

    For the Kerr-Bertotti-Robinson black hole, the magnetic field mainly enlarges the shadow and Einstein ring while rotation mainly distorts the shadow shape, and current M87* and Sgr A* data give only weak bounds on the field.

  3. Shadow of the generalized Vaidya black hole

    gr-qc 2026-07 conditional novelty 5.0 of 10

    For self-similar Husain black holes, the barotropic index α controls the shadow: α<1/2 enlarges it, α>1/2 shrinks it, with a quasistatic influx criterion for the time-dependent case.

  4. Probing Lorentz-violating effects via precession and accretion disk images of a rotating bumblebee black hole

    gr-qc 2026-04 conditional novelty 5.0 of 10

    Lorentz violation in a rotating bumblebee black hole suppresses Lense-Thirring precession, increases periastron precession, shrinks the inner shadow, and enhances the lensed ring while leaving the critical curve nearl...

  5. Optical and orbital characterization of spherically symmetric static black holes of self-gravitating new nonlinear electrodynamics model

    gr-qc 2026-03 conditional novelty 4.0 of 10

    PINLED Y^n black holes have charge-driven inward shifts of photon sphere, shadow, and ISCO, with null-geodesic observables distinguishing them from RN more clearly than timelike ones.

  6. Image of a quantum-corrected black hole without Cauchy horizons illuminated by a static thin accretion disk

    gr-qc 2025-10 conditional novelty 4.0 of 10

    For the no-Cauchy-horizon quantum-corrected metric, a larger quantum parameter produces larger horizon, photon sphere, ISCO, and shadow, with narrower and tighter-spaced photon and lensed rings.

Pith tools