Pith. sign in

REVIEW 4 major objections 3 minor 1 cited by

Light propagation and quasinormal modes of a topologically charged Schwarzschild-Klinkhamer wormhole

T0 review · 4 major / 3 minor · reviewed 2026-08-03 · deepseek-v4-flash

Pith's one-line read A defect wormhole's throat leaves no imprint in weak-field lensing; the global monopole charge shifts the deflection, the Einstein ring, and the relativistic images.

desk verdict Useful QNM work undercut by a wrong weak-field deflection limit and an unaddressed boundary-condition issue. read the letter →

arxiv 2601.16305 v2 pith:PVU2PUIY submitted 2026-01-22 gr-qc hep-th

classification gr-qchep-th MSC 83C5783C10
keywords defectwormholeglobalmonopolegravitationallensingdeflectionangleEinsteinringshadowradiusquasinormalmodesscalarperturbations
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper studies a traversable wormhole built from a geometric defect rather than exotic matter, with a global monopole charge. Its central claim is that the throat radius does not appear in weak-field lensing: the photon deflection, the shadow radius, and the Einstein-ring position depend on the mass and on the monopole charge, and they reduce to Schwarzschild values when the charge is switched off. The charge does shift the observables, and the paper gives explicit numerical values for angular separations, image-flux ratios, and Einstein-ring radii across the allowed charge range. Strong-field deflection, treated with the standard logarithmic-divergence expansion, likewise feels the charge but not the throat radius. Quasinormal modes and time-domain evolution, by contrast, do depend on the throat radius: larger throats give longer-lived scalar ringing. A sympathetic reader therefore learns that lensing and shadow observations can constrain the global monopole charge while ringdown can probe the throat.

What carries the argument

The central object is the metric functions Sigma^2(r)=r^2+a^2, f(r)=1-2M/Sigma(r), and g(r)=alpha^2 Sigma^2(r)/r^2, where a is the throat radius and alpha is the global monopole charge. The weak-field deflection is derived by introducing u=1/Sigma(r), which converts the orbit integral into a polynomial form and allows a second-order mass expansion. The strong-field divergent part comes from expanding the orbit equation around the photon-sphere radius r_m=sqrt(9M^2-a^2) and separating the logarithmically singular term. Quasinormal modes are computed from the tortoise coordinate r* = (sqrt(r^2+a^2)+2M ln(sqrt(r^2+a^2)-2M))/alpha and the scalar effective potential V_s=f(r)[l(l+1)/Sigma^2+2alpha

What would settle it

Compute the scalar perturbation equation on the full two-sided wormhole with outgoing boundary conditions at both r goes to plus and minus infinity and compare the resulting complex frequencies with the paper's tables; any discrepancy beyond WKB error would falsify the reported spectrum. Separately, numerically integrate the exact orbit equation for several nonzero a at fixed alpha and M/beta, and check whether the deflection matches the paper's Eq. (33) to second order; a residual a-dependence would falsify the claimed throat-blindness.

Watch

Extended reading notes

Core claim

The paper claims that for the defect wormhole metric with areal function Sigma(r)=sqrt(r^2+a^2), mass M, and global-monopole parameter alpha, the weak-field deflection angle is delta-phi approximately (1/alpha)[pi(1-alpha)+4M/beta+M^2(15pi-16)/(4 beta^2)], independent of the throat radius a and reducing to the known Schwarzschild expansion when alpha=1. The shadow radius is 3sqrt(3)M, also independent of a and alpha at this order. In the strong-field limit, the logarithmically divergent part of the deflection is derived analytically and the regular part is obtained numerically, giving relativistic-image observables controlled by alpha. For scalar perturbations, the effective potential and to

Load-bearing premise

The quasinormal-mode calculation assumes the usual black-hole WKB boundary conditions (purely outgoing waves at spatial infinities) even though, for a>2M, the tortoise coordinate has a finite minimum at the throat and the spacetime is two-sided; if those boundary conditions are not valid, the tabulated frequencies are not the actual wormhole modes.

Editorial extensions

If this is right

  • Weak-field lensing cannot distinguish this wormhole from a Schwarzschild black hole by throat radius alone: the deflection angle, shadow radius, and Einstein-ring radius all match the Schwarzschild values once the monopole charge is set to unity.
  • If the monopole charge differs from unity, the Einstein ring is enlarged or shifted; for the paper's bulge-star distances, a charge of 0.95 gives an Einstein radius roughly three orders of magnitude larger than the charge-free value.
  • Relativistic images in the strong-field limit carry a clean charge signature: lowering alpha from 1 to 0.65 increases the angular separation from 0.033 to about 3.9 microarcsec and changes the flux ratio by roughly 2.4 magnitudes.
  • Scalar ringdown frequencies are sensitive to both parameters: larger throat radii reduce the frequency and the damping, so a longer-lived ringdown could indicate a larger throat.
  • The reported quasinormal frequencies are stable in the time-domain simulation, with exponential damping followed by a power-law tail across all explored a and alpha.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The throat-blindness of weak-field lensing is likely tied to the simple Sigma^2=r^2+a^2 choice; other black-bounce or wormhole area functions would generically introduce a-dependence at low order, so this is not a universal property of wormholes.
  • The paper's parameter separation suggests a two-step observational test: use the Einstein-ring or relativistic-image observables to constrain alpha, and use the ringdown damping to constrain a; consistency across both channels would support the model.
  • A direct numerical integration of the exact null geodesics for several nonzero a at fixed alpha and M/beta would settle whether the weak-field deflection is genuinely independent of a at all orders, going beyond the paper's second-order expansion.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 3 minor

Summary. The paper analyses null geodesics, photon sphere and shadow, weak- and strong-field deflection, gravitational lensing observables, and scalar quasinormal modes for a Schwarzschild-Klinkhamer wormhole with a global monopole charge. Two independent weak-field deflection formulas are derived, a strong-field expansion is built with the Bozza/Tsukamoto method, and Einstein-ring/relativistic-image observables are constructed. The quasinormal-mode section uses a sixth-order WKB code and time-domain evolutions.

Significance. If valid, the paper would provide a useful phenomenological comparison of defect-wormhole lensing and ringdown with Schwarzschild. The manuscript contains explicit analytical formulas, numerical tables, and time-domain profiles, and it engages with standard techniques. However, the central weak-field formula contradicts the paper's own Gauss-Bonnet result, and the quasinormal-mode calculation applies black-hole boundary conditions to a wormhole without justification. These are load-bearing issues that make the current version unreliable.

major comments (4)
  1. [§V.A, Eq. (33); §V.B.2, Eq. (45); §VI.B] Setting ᾱ=1 in Eq. (33) gives δϕ = 4M/β + (15π−16)M²/(4β²), not the standard Schwarzschild second-order coefficient 15πM²/(4β²). Eq. (45) gives the correct standard limit. Thus the two weak-field formulas are mutually inconsistent at O(M²), and the statement that Eq. (33) recovers the Schwarzschild result up to second order is false. Since Eq. (33) is used in Fig. 2 and is the basis of the weak-field lensing observables, the second-order lensing claims are unsupported. The first-order Einstein ring is unaffected, but the expansion must be corrected and the discrepancy addressed.
  2. [§VII, Eqs. (80) and (85); Tables IV–V] For a>2M the spacetime has no event horizon, and the tortoise coordinate in Eq. (80) has a finite minimum at the throat and tends to +∞ at both r→±∞. The effective potential (84) does not vanish at the throat. The WKB condition (85) is derived for black-hole potentials with scattering boundary conditions at r*→±∞. Applying it to this wormhole requires a derivation with the appropriate wormhole boundary conditions (e.g., outgoing at both asymptotic regions and a junction condition at the throat). Without this, the frequencies in Tables IV–V cannot be interpreted as quasinormal modes of the wormhole.
  3. [§V.C, Eqs. (54)–(55)] The argument of the logarithm in Eq. (55), written as 'β√27M²−1', is dimensionally inconsistent and cannot be evaluated as printed. From Eq. (58) the intended quantity is clearly β/β_c −1 = β/(3√3M)−1. This is a central strong-field formula, so the typo blocks reproduction. The derivation leading to Eq. (55) should be checked and the final expression corrected.
  4. [§VI.B, Table III] The text says the weak-field lensing setup is a bulge star with DOL=4 kpc and DOS=8 kpc, citing Ref. [109]. For a solar-mass lens these distances give an Einstein radius of order milliarcseconds. Table III reports θE=2.12 arcsec for ᾱ=1, which corresponds to M≈4.4×10^6 M_sun (the Galactic-center mass used in §VI.A), not a bulge star. The mass used in Table III is not stated, and the numerical values are inconsistent with the stated setup. The table and the surrounding text must be reconciled.
minor comments (3)
  1. [§IX] The conclusion refers to Eq. (33) as the strong-field deflection angle and states that it does not depend on the throat parameter. Eq. (33) is the weak-field deflection; the strong-field formulas, Eqs. (55)–(56) and Fig. 5, do depend on a through 9M²−a² and the regular part. This mislabeling should be corrected.
  2. [§VI.B, Eq. (71)] The notation '± 1/2 !' is garbled and should be cleaned up. The algebraic structure of the Einstein-ring formula would be clearer with explicit parentheses.
  3. [§VII, Eq. (80)] The tortoise coordinate contains ln(√(a²+r²)−2M), whose argument has dimensions of length. An arbitrary scale should be introduced to make the logarithm dimensionless, or the expression should be written with a dimensionless ratio.

Circularity Check

0 steps flagged · score 2.0 of 10

No significant circularity: lensing observables and QNM spectra are derived from the metric via standard external methods; self-citations are non-load-bearing. The Eq. (33)/Eq. (45) second-order mismatch is a correctness issue, not circularity.

full rationale

The derivation chain is self-contained. The spacetime model (Eq. 10) is attributed to external sources (Refs. [46–48], Klinkhamer/Wang; the topologically charged embedding to external Ref. [90]), not to the present authors. The weak-field deflection Eq. (33) is obtained by expanding the geodesic integral Eq. (32), which follows algebraically from Eqs. (28)–(31); the Gauss–Bonnet deflection Eq. (45) is computed from the curvature Eq. (43); the strong-field deflection Eqs. (55)–(56) use Λ1, Λ2 and β(r0) expanded around rm = √(9M²−a²), all derived from the metric functions; the lensing observables (Sec. VI) follow from standard Bozza/Tsukamoto lens equations; and the QNM frequencies (Tables IV–V) come from the effective potential Eq. (84) evaluated with the externally maintained WKB code of Ref. [78]. No parameter is fitted to a target observable, and no claimed prediction is reused as an input. The ᾱ→1 Schwarzschild limits and the M→0 monopole limit are re-derived in-paper, so self-citations for those limits (e.g., Refs. [49], [74], [90], [103]) are corroboration, not load-bearing support. I found no step in which a result reduces by construction to a fitted value or to a self-citation chain. Two genuine internal inconsistencies exist — Eq. (33) at ᾱ=1 gives a second-order coefficient (15π−16)/4 that disagrees with Eq. (45)'s 15π/4 and with the stated Schwarzschild benchmark, and Eq. (71) drops a 1/ᾱ factor in the mass term — but these are correctness/consistency defects, not circularity, and they do not affect the first-order Einstein-ring or WKB results. Score 2 reflects the presence of many non-load-bearing self-citations, not any circular reduction.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The paper introduces no new particles or forces; the geometric defect and global monopole are borrowed from prior work. The main free parameters are the model's own mass, throat radius, and monopole charge, scanned by hand. The most fragile structural assumption is the unexamined use of black-hole WKB boundary conditions for a horizonless wormhole.

free parameters (3)
  • M (mass) = 1 (set in numerical sections)
    Mass of the wormhole; not fitted, but chosen as M=1 for all numerical work. A physical input parameter of the metric.
  • a (throat radius) = varied (e.g., 2.01–2.5)
    Wormhole throat parameter in Σ²=r²+a²; varied by hand to study parameter dependence. Not fitted to data.
  • ᾱ (global monopole charge) = varied in (0,1] (e.g., 0.5–1)
    Monopole charge controlling the deficit angle; scanned to show dependence of observables. Not fitted.
assumptions (4)
  • domain assumption The metric functions in Eq. (10) describe a valid topologically charged Schwarzschild-Klinkhamer wormhole sourced by a geometric defect (from Refs. [46–48]).
    The paper does not derive the field equations or energy conditions; it takes the metric from prior work by the same group and treats it as the background.
  • domain assumption The validity ranges 0<ᾱ≤1 and a>2M define the traversable wormhole regime.
    Stated in Section III; the QNM and lensing computations use parameters in these ranges without further justification.
  • domain assumption The Gauss–Bonnet deflection formula with an additional deficit-angle term (Refs. [87,92]) applies to this spacetime.
    Used to derive Eq. (45); the applicability to a global-monopole-modified wormhole with the extra π(1/ᾱ−1) term is assumed from prior literature.
  • ad hoc to paper The WKB method for quasinormal modes, with the usual black-hole boundary conditions, is valid for a traversable wormhole with a>2M (no event horizon).
    Section VII applies the 6th-order WKB formula (Eq. 85) without discussing that for a>2M the tortoise coordinate r* in Eq. (80) has a finite minimum at the throat, so the potential does not extend to −∞ and the standard QNM boundary conditions are not automatically satisfied.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Light propagation and quasinormal modes of a topologically charged Schwarzschild-Klinkhamer wormhole." pith.science (2026). https://pith.science/paper/PVU2PUIY

@misc{pith2026260116305,
  author       = {Pith},
  title        = {Pith review of: Light propagation and quasinormal modes of a topologically charged Schwarzschild-Klinkhamer wormhole},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/PVU2PUIY}},
  note         = {Machine review of arXiv:2601.16305}
}
read the original abstract

In this work, we present a theoretical analysis of null geodesics, critical photon orbits, and shadow formation associated with a wormhole generated by a geometric defect. The propagation of light in this spacetime is examined through the deflection angle in both weak- and strong-field regimes. Analytical expansions are derived in each regime and employed to characterize gravitational lensing observables. By varying the global monopole charge, we evaluate its impact on these observables and determine parameter ranges that may be accessible to current or future observational probes. Finally, we calculate the quasinormal modes as well as the time-domain solution for scalar perturbations as well.

Figures

Figures reproduced from arXiv: 2601.16305 by the authors.

Figure 1
Figure 1. FIG. 1: Null geodesics are displayed for several combinations of the parameters [PITH_FULL_IMAGE:figures/full_fig_p009_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2: Light deflection in the weak-field regime. [PITH_FULL_IMAGE:figures/full_fig_p013_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3: The Gaussian curvature [PITH_FULL_IMAGE:figures/full_fig_p016_3.png] view at source ↗
Figures from the paper (9 more)
Figure 4
Figure 4. Figure 4: FIG. 4: The deflection angle ˆα [PITH_FULL_IMAGE:figures/full_fig_p017_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5: In (a) and (b) we have respectively the regular part of the integration ( [PITH_FULL_IMAGE:figures/full_fig_p020_5.png]
Figure 6
Figure 6. Figure 6: FIG. 6: In (a) and (b) we have the angular deviation as a function of the impact parameter [PITH_FULL_IMAGE:figures/full_fig_p020_6.png]
Figure 7
Figure 7. Figure 7: FIG. 7: Light angular deflection diagram. [PITH_FULL_IMAGE:figures/full_fig_p021_7.png]
Figure 8
Figure 8. Figure 8: FIG. 8: In (a) we have the angular separation [PITH_FULL_IMAGE:figures/full_fig_p024_8.png]
Figure 9
Figure 9. Figure 9: FIG. 9: The effective potential governing scalar perturbations is shown as a function of the [PITH_FULL_IMAGE:figures/full_fig_p028_9.png]
Figure 10
Figure 10. Figure 10: FIG. 10: Numerical profiles of the scalar perturbation [PITH_FULL_IMAGE:figures/full_fig_p032_10.png]
Figure 11
Figure 11. Figure 11: FIG. 11: Logarithmic time–domain signals, ln [PITH_FULL_IMAGE:figures/full_fig_p032_11.png]
Figure 12
Figure 12. Figure 12: FIG. 12: Asymptotic time–domain behavior of the scalar field [PITH_FULL_IMAGE:figures/full_fig_p033_12.png]

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

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

  1. Branch structure and nonextensive thermodynamics of Kalb-Ramond-ModMax black holes: observational signatures

    gr-qc 2026-01 reject novelty 4.0 of 10

    A multi-channel phenomenological study of Einstein-Kalb-Ramond-ModMax black holes whose Tsallis internal energy does not reduce to the black-hole mass in the standard-entropy limit.

Reference graph

Works this paper leans on

124 extracted references · 1 linked inside Pith · cited by 1 Pith paper

  1. [109]

    The Galactic Center Massive Black Hole and Nuclear Star Cluster.Rev

    Reinhard Genzel, Frank Eisenhauer, and Stefan Gillessen. The Galactic Center Massive Black Hole and Nuclear Star Cluster.Rev. Mod. Phys., 82:3121–3195, 2010

  2. [1]

    Their dynamical behavior is not fixed by symmetry alone but is instead controlled by how nearby null trajec- tories respond to small deviations from circular motion

    Stability of the critical orbits Photon rings, also referred to as critical light orbits, emerge as a consequence of the geo- metric structure encoded in the optical manifold associated with a spacetime. Their dynamical behavior is not fixed by symmetry alone but is instead controlled by how nearby null trajec- tories respond to small deviations from circ...

  3. [2]

    DLSπ(1−¯α) 2 ¯αDOS # ± 1 2 !

    Weak deflection angle The bending of light in the weak-field regime is evaluated through a geometric procedure based on the Gauss–Bonnet theorem [91]. The calculation makes direct use of the curvature given in Eq. (43). For practical implementation, the optical geometry is projected onto the equatorial section by fixingθ=π/2, which effectively yields a tw...

  4. [3]

    Schwarzschild

    K. Schwarzschild. About the gravitational field of a mass point according to einstein’s theory. Berlin. Session Reports, 18, 1916

  5. [4]

    R. Penrose. Gravitational collapse and space-time singularities.Phys. Rev. Lett., 14:57–59, 1965. 35

  6. [5]

    R. M. Wald.General Relativity. The University of Chicago Press, Chicago, 1984

  7. [6]

    D’Inverno.Introducing Einstein ’s Relativity

    R. D’Inverno.Introducing Einstein ’s Relativity. Oxford University Press, New York, 1998

  8. [7]

    J. M. Bardeen. Non-singular general relativistic gravitational collapse. InProceedings of the International Conference GR5, Tbilisi, U.S.S.R., 1968

Show all 124 references
  1. [8]

    E. M. Rodrigues and M. V. de S. Silva. Bardeen Regular Black Hole With an Electric Source. J. Cosmol. Astropart. Phys., 06:025, 2018

  2. [9]

    The Bardeen model as a nonlinear magnetic monopole

    Eloy Ayon-Beato and Alberto Garcia. The Bardeen model as a nonlinear magnetic monopole. Phys. Lett. B, 493:149–152, 2000

  3. [10]

    Regular black hole in general relativity coupled to non- linear electrodynamics.Phys

    Eloy Ayon-Beato and Alberto Garcia. Regular black hole in general relativity coupled to non- linear electrodynamics.Phys. Rev. Lett., 80:5056–5059, 1998

  4. [11]

    New regular black hole solution from nonlinear electro- dynamics.Phys

    Eloy Ayon-Beato and Alberto Garcia. New regular black hole solution from nonlinear electro- dynamics.Phys. Lett. B, 464:25, 1999

  5. [12]

    K. A. Bronnikov. Comment on ‘Regular black hole in general relativity coupled to nonlinear electrodynamics’.Phys. Rev. Lett., 85:4641, 2000

  6. [13]

    Bronnikov

    Kirill A. Bronnikov. Regular magnetic black holes and monopoles from nonlinear electrodynam- ics.Phys. Rev. D, 63:044005, 2001

  7. [14]

    Regular electrically charged structures in nonlinear electrodynamics coupled to general relativity.Class

    Irina Dymnikova. Regular electrically charged structures in nonlinear electrodynamics coupled to general relativity.Class. Quant. Grav., 21:4417–4429, 2004

  8. [15]

    Four parametric regular black hole solution.Gen

    Eloy Ayon-Beato and Alberto Garcia. Four parametric regular black hole solution.Gen. Rel. Grav., 37:635, 2005

  9. [16]

    Sean A. Hayward. Formation and evaporation of regular black holes.Phys. Rev. Lett., 96:031103, 2006

  10. [17]

    New solutions of charged regular black holes and their stability.Phys

    Nami Uchikata, Shijun Yoshida, and Toshifumi Futamase. New solutions of charged regular black holes and their stability.Phys. Rev. D, 86:084025, 2012

  11. [18]

    Nonsingular black hole with a nonlinear electric source.Int

    Hristu Culetu. Nonsingular black hole with a nonlinear electric source.Int. J. Mod. Phys. D, 24(09):1542001, 2015

  12. [19]

    Leonardo Balart and Elias C. Vagenas. Regular black holes with a nonlinear electrodynamics source.Phys. Rev. D, 90(12):124045, 2014

  13. [20]

    Leonardo Balart and Elias C. Vagenas. Regular black hole metrics and the weak energy condi- tion.Phys. Lett. B, 730:14–17, 2014

  14. [21]

    Construction of regular black holes in general relativity

    Kirill A. Bronnikov. Comment on “Construction of regular black holes in general relativity”. Phys. Rev. D, 96(12):128501, 2017

  15. [22]

    Ponce de Leon

    J. Ponce de Leon. Regular Reissner-Nordstr¨ om black hole solutions from linear electrodynamics. Phys. Rev. D, 95(12):124015, 2017. 36

  16. [23]

    Rodrigues, Ednaldo L

    Manuel E. Rodrigues, Ednaldo L. B. Junior, and Marcos V. de Sousa Silva. Using dominant and weak energy conditions for build new classe of regular black holes.JCAP, 02:059, 2018

  17. [24]

    Black-bounce to traversable wormhole.JCAP, 02:042, 2019

    Alex Simpson and Matt Visser. Black-bounce to traversable wormhole.JCAP, 02:042, 2019

  18. [25]

    Bronnikov and Rahul Kumar Walia

    Kirill A. Bronnikov and Rahul Kumar Walia. Field sources for Simpson-Visser spacetimes.Phys. Rev. D, 105(4):044039, 2022

  19. [26]

    Charged Ellis Wormhole and Black Bounce.Phys

    Hyat Huang and Jinbo Yang. Charged Ellis Wormhole and Black Bounce.Phys. Rev. D, 100(12):124063, 2019

  20. [27]

    Vaidya spacetimes, black-bounces, and traversable wormholes.Class

    Alex Simpson, Prado Martin-Moruno, and Matt Visser. Vaidya spacetimes, black-bounces, and traversable wormholes.Class. Quant. Grav., 36(14):145007, 2019

  21. [28]

    Francisco S. N. Lobo, Manuel E. Rodrigues, Marcos V. de Sousa Silva, Alex Simpson, and Matt Visser. Novel black-bounce spacetimes: wormholes, regularity, energy conditions, and causal structure.Phys. Rev. D, 103(8):084052, 2021

  22. [29]

    Charged black-bounce spacetimes.JCAP, 07:036, 2021

    Edgardo Franzin, Stefano Liberati, Jacopo Mazza, Alex Simpson, and Matt Visser. Charged black-bounce spacetimes.JCAP, 07:036, 2021

  23. [30]

    A novel family of rotating black hole mimickers.JCAP, 04:082, 2021

    Jacopo Mazza, Edgardo Franzin, and Stefano Liberati. A novel family of rotating black hole mimickers.JCAP, 04:082, 2021

  24. [31]

    Rodrigues and Marcos V

    Manuel E. Rodrigues and Marcos V. de S. Silva. Embedding regular black holes and black bounces in a cloud of strings.Phys. Rev. D, 106(8):084016, 2022

  25. [32]

    Bronnikov, Manuel E

    Kirill A. Bronnikov, Manuel E. Rodrigues, and Marcos V. de S. Silva. Cylindrical black bounces and their field sources.Phys. Rev. D, 108(2):024065, 2023

  26. [33]

    A. Lima, G. Alencar, R. N. Costa Filho, and R. R. Landim. Charged black string bounce and its field source.Gen. Rel. Grav., 55(10):108, 2023

  27. [34]

    Black String Bounce to Traversable Wormhole.Symmetry, 15(1):150, 2023

    Arthur Menezes Lima, Geov´ a Maciel de Alencar Filho, and Job Saraiva Furtado Neto. Black String Bounce to Traversable Wormhole.Symmetry, 15(1):150, 2023

  28. [35]

    Rodrigues and Marcos V

    Manuel E. Rodrigues and Marcos V. de S. Silva. Source of black bounces in general relativity. Phys. Rev. D, 107(4):044064, 2023

  29. [36]

    Fabris, Ednaldo L

    J´ ulio C. Fabris, Ednaldo L. B. Junior, and Manuel E. Rodrigues. Generalized models for black- bounce solutions in f(R) gravity.Eur. Phys. J. C, 83(10):884, 2023

  30. [37]

    Ednaldo L. B. Junior and Manuel E. Rodrigues. Black-bounce in f(T) gravity.Gen. Rel. Grav., 55(1):8, 2023

  31. [38]

    A. Lima, G. Alencar, and Diego S´ aez-Chillon G´ omez. Regularizing rotating black strings with a new black-bounce solution.Phys. Rev. D, 109(6):064038, 2024

  32. [39]

    Carlos F. S. Pereira, Denis C. Rodrigues, J´ ulio C. Fabris, and Manuel E. Rodrigues. Black- bounce solution in k-essence theories.Phys. Rev. D, 109(4):044011, 2024. 37

  33. [40]

    Jos´ e Tarciso S. S. Junior, Francisco S. N. Lobo, and Manuel E. Rodrigues. Black bounces in conformal Killing gravity.Eur. Phys. J. C, 84(6):557, 2024

  34. [41]

    Ednaldo L. B. Junior, Jos´ e Tarciso S. S. Junior, Francisco S. N. Lobo, Manuel E. Rodrigues, Diego Rubiera-Garcia, Lu ´ ıs F. Dias da Silva, and Henrique A. Vieira. Black bounces in Cotton gravity.Eur. Phys. J. C, 84(11):1190, 2024

  35. [42]

    Carlos F. S. Pereira, Denis C. Rodrigues, ´Ebano L. Martins, J´ ulio C. Fabris, and Manuel E. Rodrigues. New sources of ghost fields in k-essence theories for black-bounce solutions.Class. Quant. Grav., 42(1):015001, 2025

  36. [43]

    Alencar, Kirill A

    G. Alencar, Kirill A. Bronnikov, Manuel E. Rodrigues, Diego S´ aez-Chill´ on G´ omez, and Mar- cos V. de S. Silva. On black bounce space-times in non-linear electrodynamics.Eur. Phys. J. C, 84(7):745, 2024

  37. [44]

    Marcos V. de S. Silva, T. M. Crispim, G. Alencar, R. R. Landim, and Manuel E. Rodrigues. Generalized black-bounces solutions in f(R) gravity and their field sources.Class. Quant. Grav., 43(1):015005, 2026

  38. [45]

    Carlos F. S. Pereira, Denis C. Rodrigues, Marcos V. de S. Silva, J´ ulio C. Fabris, Manuel E. Rodrigues, and H. Belich. Magnetically charged black-bounce solution via nonlinear electrody- namics in a k-essence theory.Phys. Rev. D, 111(8):084025, 2025

  39. [46]

    Carlos F. S. Pereira, Marcos V. de S. Silva, H. Belich, Denis C. Rodrigues, J´ ulio C. Fabris, and Manuel E. Rodrigues. Black-bounce solutions in a k-essence theory under the effects of bumblebee gravity.Phys. Rev. D, 111(12):124005, 2025

  40. [47]

    Rodrigues and Marcos V

    Manuel E. Rodrigues and Marcos V. de S. Silva. Spherically symmetric and static black bounces with multiple horizons, throats, and anti-throats in four dimensions.Class. Quant. Grav., 42(5):055005, 2025

  41. [48]

    F. R. Klinkhamer. Defect wormhole: A traversable wormhole without exotic matter.Acta Phys. Polon. B, 54:5–A3, 2023

  42. [49]

    F. R. Klinkhamer. Vacuum-defect wormholes and a mirror world.Acta Phys. Polon. B, 54:7–A3, 2023

  43. [50]

    Z. L. Wang. On a schwarzschild-type defect wormhole. 2023

  44. [51]

    J. R. Nascimento, A. Yu. Petrov, P. J. Porfirio, and A. R. Soares. Gravitational lensing in black-bounce spacetimes.Phys. Rev. D, 102(4):044021, 2020

  45. [52]

    Tsukamoto

    N. Tsukamoto. Gravitational lensing by two photon spheres in a black-bounce spacetime in strong deflection limits.Phys. Rev. D, 104:064022, 2021

  46. [53]

    Tsukamoto

    N. Tsukamoto. Gravitational lensing in the simpson-visser black-bounce spacetime in a strong deflection limit.Phys. Rev. D, 103:024033, 2021. 38

  47. [54]

    Tsukamoto

    N. Tsukamoto. Retrolensing by two photon spheres of a black-bounce spacetime.Phys. Rev. D, 105:084036, 2022

  48. [55]

    Ghosh and A

    S. Ghosh and A. Bhattacharyya. Analytical study of gravitational lensing in kerr-newman black-bounce spacetime.J. Cosmol. Astropart. Phys., 11:006, 2022

  49. [56]

    G. He, Y. Xie, C. Jiang, and W. Lin. Gravitational lensing of massive particles by a black- bounce-schwarzschild black hole.Phys. Rev. D, 110(6):064008, 2024

  50. [57]

    C. F. S. Pereira, A. R. Soares, M. V. de S. Silva, R. L. L. Vit´ oria, and H. Belich. Light deflection and gravitational lensing effects in acoustic black-bounce spacetime.Phys. Rev. D, 112(6):064012, 2025

  51. [58]

    H. C. D. Lima, C. L. Benone, and L. C. B. C. Crispino. Scalar scattering by black holes and wormholes.Eur. Phys. J. C, 82(7):638, 2022

  52. [59]

    Quasinormal modes and echoes of generalized black hole bounces and their correspondence with shadows

    Albert Duran-Cabac´ es, Diego Rubiera-Garcia, and Diego S´ aez-Chill´ on G´ omez. Quasinormal modes and echoes of generalized black hole bounces and their correspondence with shadows. Phys. Rev. D, 112(4):044016, 2025

  53. [60]

    Lens-Like Action of a Star by the Deviation of Light in the Gravitational Field

    Albert Einstein. Lens-Like Action of a Star by the Deviation of Light in the Gravitational Field. Science, 84:506–507, 1936

  54. [61]

    Gravitational lenses.Physical Review, 133(3B):B835, 1964

    Sidney Liebes Jr. Gravitational lenses.Physical Review, 133(3B):B835, 1964

  55. [62]

    The gravity field of a particle.Proceedings of the Royal Society of London

    Charles Galton Darwin. The gravity field of a particle.Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 249(1257):180–194, 01 1959

  56. [63]

    Atkinson.Astron

    R. Atkinson.Astron. J., 70:517, 1965

  57. [64]

    K. S. Virbhadra and George F. R. Ellis. Schwarzschild black hole lensing.Phys. Rev. D, 62:084003, 2000

  58. [65]

    V. Bozza. Gravitational lensing in the strong field limit.Phys. Rev. D, 66:103001, 2002

  59. [66]

    Deflection angle in the strong deflection limit in a general asymptotically flat, static, spherically symmetric spacetime.Phys

    Naoki Tsukamoto. Deflection angle in the strong deflection limit in a general asymptotically flat, static, spherically symmetric spacetime.Phys. Rev. D, 95(6):064035, 2017

  60. [67]

    Cambrigde

    A. Vilenkin and E. P. S. Shellard.Strings and Other Topological Defects. Cambridge University Press, Cambridge, 1994. Spelling in source: “Cambrigde”; standardized to Cambridge

  61. [68]

    Manton and P

    N. Manton and P. Sutcliffe.Topological Solitons. Cambridge Monographs on Mathematical Physics. Cambridge University Press, 2004

  62. [69]

    Oxford University Press, 2007

    Tanmay Vachaspati.Kinks and Domain Walls : An Introduction to Classical and Quantum Solitons. Oxford University Press, 2007

  63. [70]

    A. R. Bishop and T. Schneider, editors.Solitons in Condensed Matter Physics. Springer Verlag, Berlin, 1978

  64. [71]

    Rubakov.Classical Theory of Gauge Fields

    V. Rubakov.Classical Theory of Gauge Fields. Princeton University Press, 2009. 39

  65. [72]

    Marques and Valdir B

    Geusa de A. Marques and Valdir B. Bezerra. Hydrogen atom in the gravitational fields of topological defects.Phys. Rev. D, 66:105011, 2002

  66. [73]

    Marques and Valdir B

    Geusa de A. Marques and Valdir B. Bezerra. Nonrelativistic quantum systems on topological defects space-times.Class. Quant. Grav., 19:985–996, 2002

  67. [74]

    E. A. F. Bragan¸ ca, E. R. Bezerra de Mello, R. L. L. Vit´ oria, and H. Belich. Relativistic quantum oscillators in the global monopole spacetime.Eur. Phys. J. C, 80(3):206, 2020

  68. [75]

    C. F. S. Pereira, A. R. Soares, R. L. L. Vit´ oria, and H. Belich. Bosonic quantum dynamics in Eddington-inspired Born–Infeld gravity global monopole spacetime.Eur. Phys. J. C, 83(4):270, 2023

  69. [76]

    A. R. Soares, R. L. L. Vit´ oria, and C. F. S. Pereira. Gravitational lensing in a topologically charged Eddington-inspired Born–Infeld spacetime.Eur. Phys. J. C, 83(10):903, 2023

  70. [77]

    R. A. Konoplya and A. Zhidenko. Decay of a charged scalar and Dirac fields in the Kerr- Newman-de Sitter background.Phys. Rev. D, 76(8):084018, 2007. [Erratum: Phys.Rev.D 90, 029901 (2014)]

  71. [78]

    R. A. Konoplya and A. Zhidenko. Massive charged scalar field in the Kerr-Newman background I: quasinormal modes, late-time tails and stability.Phys. Rev. D, 88:024054, 2013

  72. [79]

    Quasinormal modes, temperatures and greybody factors of black holes in a generalized rastall gravity theory.Physica Scripta, 99(5):055003, 2024

    Ronit Karmakar and Umananda Dev Goswami. Quasinormal modes, temperatures and greybody factors of black holes in a generalized rastall gravity theory.Physica Scripta, 99(5):055003, 2024

  73. [80]

    R. A. Konoplya, A. Zhidenko, and A. F. Zinhailo. Higher order WKB formula for quasinormal modes and grey-body factors: recipes for quick and accurate calculations.Class. Quant. Grav., 36:155002, 2019

  74. [81]

    K. D. Kokkotas, R. A. Konoplya, and A. Zhidenko. Quasinormal modes, scattering and Hawking radiation of Kerr-Newman black holes in a magnetic field.Phys. Rev. D, 83:024031, 2011

  75. [82]

    R. A. Konoplya and A. Zhidenko. Quasinormal modes of black holes: From astrophysics to string theory.Rev. Mod. Phys., 83:793–836, 2011

  76. [83]

    Connection Between the Shadow Radius and Quasinormal Modes in Rotating Spacetimes.Phys

    Kimet Jusufi. Connection Between the Shadow Radius and Quasinormal Modes in Rotating Spacetimes.Phys. Rev. D, 101(12):124063, 2020

  77. [84]

    R. A. Konoplya and A. Zhidenko. Correspondence between grey-body factors and quasinormal frequencies for rotating black holes.Phys. Lett. B, 861:139288, 2025

  78. [85]

    R. A. Konoplya and A. Zhidenko. Correspondence between grey-body factors and quasinormal modes.JCAP, 09:068, 2024

  79. [86]

    V¨ olkel.Testing General Relativity with Black Hole Quasi- normal Modes

    Nicola Franchini and Sebastian H. V¨ olkel.Testing General Relativity with Black Hole Quasi- normal Modes. 2024

  80. [87]

    Influence of a plasma on 40 the shadow of a spherically symmetric black hole.Physical Review D, 92(10):104031, 2015

    Volker Perlick, Oleg Yu Tsupko, and Gennady S Bisnovatyi-Kogan. Influence of a plasma on 40 the shadow of a spherically symmetric black hole.Physical Review D, 92(10):104031, 2015

  81. [88]

    Shadow of a black hole surrounded by dark matter.Physics Letters B, 795:1–6, 2019

    RA Konoplya. Shadow of a black hole surrounded by dark matter.Physics Letters B, 795:1–6, 2019

  82. [89]

    A. A. Ara´ ujo Filho, N. Heidari, Iarley P. Lobo, and V. B. Bezerra. Gravitational aspects of a new bumblebee black hole. 11 2025

  83. [90]

    A. A. Ara´ ujo Filho, N. Heidari, I. P. Lobo, and V. B. Bezerra. Gravitational signatures of a nonlinear electrodynamics in f(R,T) gravity.JCAP, 09:015, 2025

  84. [91]

    A. A. Ara´ ujo Filho. Remarks on a nonlinear electromagnetic extension in AdS Reissner- Nordstr¨ om spacetime.JCAP, 01:072, 2025

  85. [92]

    Geodesics motion of test particles around Schwarzschild-Klinkhamer worm- hole with topological defects and gravitational lensing.JCAP, 11:010, 2023

    Faizuddin Ahmed. Geodesics motion of test particles around Schwarzschild-Klinkhamer worm- hole with topological defects and gravitational lensing.JCAP, 11:010, 2023

  86. [93]

    G. W. Gibbons and M. C. Werner. Applications of the Gauss-Bonnet theorem to gravitational lensing.Class. Quant. Grav., 25:235009, 2008

  87. [94]

    Werner, Ayan Banerjee, and Ali ¨Ovg¨ un

    Kimet Jusufi, Marcus C. Werner, Ayan Banerjee, and Ali ¨Ovg¨ un. Light Deflection by a Rotating Global Monopole Spacetime.Phys. Rev. D, 95(10):104012, 2017

  88. [95]

    Geometric approach to circular photon orbits and black hole shadows.Physical Review D, 106(2):L021501, 2022

    Chen-Kai Qiao and Ming Li. Geometric approach to circular photon orbits and black hole shadows.Physical Review D, 106(2):L021501, 2022

  89. [96]

    Heidari, A

    N. Heidari, A. A. Ara´ ujo Filho, and Iarley P. Lobo. Non-commutativity in Hayward spacetime. JCAP, 09:051, 2025

  90. [97]

    Curvatures, photon spheres, and black hole shadows.Physical Review D, 106(8):084060, 2022

    Chen-Kai Qiao. Curvatures, photon spheres, and black hole shadows.Physical Review D, 106(8):084060, 2022

  91. [98]

    A Ara´ ujo Filho, N Heidari, J

    A. A Ara´ ujo Filho, N Heidari, J. A. A. S Reis, and H Hassanabadi. The impact of an antisym- metric tensor on charged black holes: evaporation process, geodesics, deflection angle, scattering effects and quasinormal modes.Classical and Quantum Gravity, 42(6):065026, 2025

  92. [99]

    The existence and distribution of photon spheres near spherically symmetric black holes–a geometric analysis.arXiv preprint arXiv:2407.14035, 2024

    Chen-Kai Qiao. The existence and distribution of photon spheres near spherically symmetric black holes–a geometric analysis.arXiv preprint arXiv:2407.14035, 2024

  93. [100]

    A Ara´ ujo Filho

    A. A Ara´ ujo Filho. Analysis of a nonlinear electromagnetic generalization of the reissner– nordstr¨ om black hole.The European Physical Journal C, 85(4):454, 2025

  94. [101]

    A. A. Ara´ ujo Filho, N. Heidari, Iarley P. Lobo, and Yuxuan Shi. Optical Phenomena in a Non-Commutative Kalb-Ramond Black Hole Spacetime. 8 2025

  95. [102]

    A. A. Ara´ ujo Filho, N. Heidari, and Iarley P. Lobo. Black Hole Gravitational Phenomena in Higher-Order Curvature-Scalar Gravity. 9 2025

  96. [103]

    A Ara´ ujo Filho, J

    A. A Ara´ ujo Filho, J. R Nascimento, A Yu Petrov, P. J Porf ´ ırio, and Ali ¨Ovg¨ un. Effects of non-commutative geometry on black hole properties.Physics of the Dark Universe, 46:101630, 41 2024

  97. [104]

    A Ara´ ujo Filho, N Heidari, and Ali ¨Ovg¨ un

    A. A Ara´ ujo Filho, N Heidari, and Ali ¨Ovg¨ un. Geodesics, accretion disk, gravitational lensing, time delay, and effects on neutrinos induced by a non-commutative black hole.Journal of Cosmology and Astroparticle Physics, 2025(06):062, 2025

  98. [105]

    A. R. Soares, C. F. S. Pereira, R. L. L. Vit´ oria, and Erick Melo Rocha. Holonomy corrected Schwarzschild black hole lensing.Phys. Rev. D, 108(12):124024, 2023

  99. [106]

    A. R. Soares, C. F. S. Pereira, R. L. L. Vit´ oria, Marcos V. de S. Silva, and H. Belich. Light deflection and gravitational lensing effects inspired by loop quantum gravity.JCAP, 06:034, 2025

  100. [107]

    V. Bozza. Quasiequatorial gravitational lensing by spinning black holes in the strong field limit. Phys. Rev. D, 67:103006, 2003

  101. [108]

    Vazquez and Ernesto P

    Samuel E. Vazquez and Ernesto P. Esteban. Strong field gravitational lensing by a Kerr black hole.Nuovo Cim. B, 119:489–519, 2004

  102. [110]

    Einstein radii from binary source events.Astrophys

    Cheongho Han and Andrew Gould. Einstein radii from binary source events.Astrophys. J., 480:196, 1997

  103. [111]

    F. Abe. Gravitational Microlensing by the Ellis Wormhole.Astrophys. J., 725:787–793, 2010

  104. [112]

    Alana C. L. Santos, Leandro A. Lessa, Roberto V. Maluf, and Gonzalo J. Olmo. Echoes and quasinormal modes of asymmetric black bounces. 8 2025

  105. [113]

    Price, and Jorge Pullin

    Carsten Gundlach, Richard H. Price, and Jorge Pullin. Late time behavior of stellar collapse and explosions: 1. Linearized perturbations.Physical Review D, 49:883–889, 1994

  106. [114]

    S. V. Bolokhov. Late time decay of scalar and Dirac fields around an asymptotically de Sit- ter black hole in the Euler–Heisenberg electrodynamics.The European Physical Journal C, 84(6):634, 2024

  107. [115]

    Ringing of extreme regular black holes.Gravitation and Cosmology, 30(3):279–288, 2024

    Milena Skvortsova. Ringing of extreme regular black holes.Gravitation and Cosmology, 30(3):279–288, 2024

  108. [116]

    Quasinormal modes and greybody factor of a Lorentz- violating black hole.Journal of Cosmology and Astroparticle Physics,, 07:008, 2024

    Wen-Di Guo, Qin Tan, and Yu-Xiao Liu. Quasinormal modes and greybody factor of a Lorentz- violating black hole.Journal of Cosmology and Astroparticle Physics,, 07:008, 2024

  109. [117]

    Quasinormal modes and bounding greybody factors of GUP-corrected black holes in Kalb–Ramond gravity.Annals of Physics, 455:169393, 2023

    Anshuman Baruah, Ali ¨Ovg¨ un, and Atri Deshamukhya. Quasinormal modes and bounding greybody factors of GUP-corrected black holes in Kalb–Ramond gravity.Annals of Physics, 455:169393, 2023

  110. [118]

    Cai-Ying Shao, Cong Zhang, Wei Zhang, and Cheng-Gang Shao. Scalar fields around a loop quantum gravity black hole in de Sitter spacetime: Quasinormal modes, late-time tails and 42 strong cosmic censorship.Physical Review D, 109(6):064012, 2024

  111. [119]

    B. C. L¨ utf¨ uo˘ glu. Long-lived quasinormal modes, grey-body factors and absorption cross-section of the black hole immersed in the Hernquist galactic halo. 10 2025

  112. [120]

    Echoes of massless scalar field induced from hairy schwarzschild black hole.Physics Letters B, 853:138688, 2024

    Zhen-Hao Yang, Cheng Xu, Xiao-Mei Kuang, Bin Wang, and Rui-Hong Yue. Echoes of massless scalar field induced from hairy schwarzschild black hole.Physics Letters B, 853:138688, 2024

  113. [121]

    Yuxuan Shi and A. A. Ara´ ujo Filho. Neutrino oscillations induced by a new bumblebee black hole. 11 2025

  114. [122]

    Yuxuan Shi and A. A. Ara´ ujo Filho. Effects of bumblebee gravity on neutrino motion.JCAP, 11:045, 2025

  115. [123]

    Yuxuan Shi and A. A. Ara´ ujo Filho. Influence of a Kalb-Ramond black hole on neutrino behavior. JHEP, 08:028, 2025

  116. [124]

    A. A. Ara´ ujo Filho, N. Heidari, and Yuxuan Shi. Neutrino dynamics in a non-commutative spacetime. 4 2025

Pith tools

Reviewed August 3, 2026 · model on record in the stance chip above.