pith. sign in

arxiv: 2602.01111 · v2 · submitted 2026-02-01 · 🌀 gr-qc · hep-th

Charged nutty black holes are hairy

Pith reviewed 2026-05-16 09:02 UTC · model grok-4.3

classification 🌀 gr-qc hep-th
keywords black holesMisner stringselectromagnetic hairNUT parametermonopolescharged black holesgeneral relativity
0
0 comments X

The pith

Charged nutty black holes carry electromagnetic hair produced by singular flows on Misner strings.

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

The paper shows that the electric and magnetic monopoles on Misner strings of charged nutty black holes arise from singular, nonuniform flows of electric and magnetic fields. These flows have nonzero divergence, which acts like effective charge densities along the strings. This creates a short-range electromagnetic hair zone around the horizon, rendering the combined Misner-Dirac strings observable in classical terms. Rotation can generate similar hair even without the NUT parameter. A sympathetic reader would care because it supplies a concrete classical mechanism that lets certain black holes evade the no-hair expectation through observable field structure.

Core claim

The electric and magnetic monopoles discovered on Misner strings accompanying charged nutty black holes are produced by singular nonuniform flows of electric and magnetic fields with nonzero divergence, thereby simulating effective charge densities and creating a complex short-range electromagnetic hair zone around the horizon, making the combined Misner-Dirac strings classically observable. Rotation can act as a hair generator even in the absence of NUT.

What carries the argument

Misner strings carrying singular nonuniform flows of electric and magnetic fields whose nonzero divergence simulates effective monopoles and produces short-range electromagnetic hair.

If this is right

  • The Misner-Dirac strings become classically observable through the surrounding hair zone.
  • Rotation alone can produce electromagnetic hair even when the NUT parameter is absent.
  • Effective electric and magnetic charge densities are simulated along the strings by the field divergences.
  • The hair zone is short-range and surrounds the horizon in a complex pattern.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • This classical hair mechanism may apply to other spacetimes containing string-like singularities.
  • The observable zone could alter how energy is extracted or how test particles interact near the horizon.
  • Similar field-flow interpretations might clarify hair in rotating or magnetized solutions without explicit monopoles.

Load-bearing premise

That the classical nonzero divergence of the singular field flows on the Misner strings can be read directly as physical charge densities without regularization or quantum corrections.

What would settle it

An explicit calculation of the electromagnetic field components near the horizon of a charged nutty black hole that shows zero divergence along the Misner strings or no short-range hair zone would falsify the interpretation.

Figures

Figures reproduced from arXiv: 2602.01111 by Dmitri Gal'tsov, Rostom Karsanov.

Figure 1
Figure 1. Figure 1: Domain of integration for fluxes of electric and magnetic fields. (The arrows indicate the directions [PITH_FULL_IMAGE:figures/full_fig_p006_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: 𝑟𝑒 < 𝑟+ ( 𝑚 = 0.75, 𝑛 = 1.2, 𝑞 = 0.5, 𝑝 = 0). Electric LFs start at the positively charged MD strings and at the horizon, spreading directly to infinity. Magnetic LFs are confined, starting form the horizon and closing on the MD strings (SH-hair) [PITH_FULL_IMAGE:figures/full_fig_p008_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: 𝑟𝑒 = 𝑟+ (𝑚 = 1, 𝑛 = 2, 𝑞 = 2, 𝑝 = 0). Electric LFs propagate from the MD strings to infinity and not touching the horizon. Magnetic field is again of the SH hair type [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: 𝑟𝑒 > 𝑟+ (𝑚 = 0.75, 𝑛 = 1.3, 𝑞 = 1.5, 𝑝 = 0). The green circle 𝑟 = 𝑟𝑒 separates the confined SH electric hair sector from the zone of LFs spreading to infinity. Magnetic hair now has both SH and SS sectors. 8 [PITH_FULL_IMAGE:figures/full_fig_p008_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: 𝑟𝑚 < 𝑟𝑒 < 𝑟+ (𝑚 = 2, 𝑛 = 1, 𝑞 = 𝑝 = 0.71). All the electric LFs starting either on the horizon or on the strings spread to infinity, while part of the magnetic LFs starting on the horizon end on Misner strings forming SH hair [PITH_FULL_IMAGE:figures/full_fig_p009_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: 𝑟𝑚 < 𝑟+, 𝑟𝑒 = 𝑟+ (𝑚 ≈ 1.21, 𝑛 = 1, 𝑞 = 𝑝 = 0.71). The electric flux throughout the horizon vanishes, so the electric charge at infinity is due to the LFs, coming from the Misner strings only [PITH_FULL_IMAGE:figures/full_fig_p009_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: 𝑟𝑚 < 𝑟+ < 𝑟𝑒 (𝑚 = 0.6, 𝑛 = 1, 𝑞 = 𝑝 = 0.71). Part of electric lines are confined between the horizon and strings (SH-hair), and part of magnetic lines starts and ends on the strings (SS-hair). 9 [PITH_FULL_IMAGE:figures/full_fig_p009_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: 𝑟𝑚 = 𝑟+, 𝑟𝑒 > 𝑟+(𝑚 ≈ 0.21, 𝑛 = 1, 𝑞 = 𝑝 = 0.71). Electric lines are partly confined (SH-hair), magnetic LFs do not touch the horizon, but contains SS-hair sector [PITH_FULL_IMAGE:figures/full_fig_p010_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: 𝑟+ < 𝑟𝑚 < 𝑟𝑒 (𝑚 = 0.15, 𝑛 = 1, 𝑞 = 𝑝 = 0.71). For both fields the MD charge densities change signs, so there are confined SH and SS hair. Kerr-Newman-NUT. The main new feature is that the charge densities at the horizon (18) can also change sign (polarization), so the HH hair can arise [PITH_FULL_IMAGE:figures/full_fig_p010_9.png] view at source ↗
Figure 10
Figure 10. Figure 10: Nutless electrically charged BH 𝑚 = 2, 𝑛 = 0, 𝑞 = 1.32, 𝑝 = 0, 𝑎 = −0.5. Magnetic charge density on the horizon, induced by rotation, has opposite signs on the northern and southern hemispheres, between which closed LFs form HH magnetic hair. 10 [PITH_FULL_IMAGE:figures/full_fig_p010_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: NUTless 𝑝 = −𝑞 rotating dyon (𝑚 = 2, 𝑛 = 0, 𝑞 = 0.1, 𝑝 = −0.1, 𝑎 = 1.99). Both electric and magnetic horizons charge densities have positive and negative sectors, between which HH-hair arise [PITH_FULL_IMAGE:figures/full_fig_p011_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: Electric rotating BH with NUT (𝑚 = 0.5, 𝑛 = 1, 𝑞 = 0.01, 𝑝 = 0, 𝑎 = −1.11). Electric: oppositely charged strings and a polarized horizon, SH and HH hair. Magnetic: South string density changes sign, SS and SH hair, full confinement [PITH_FULL_IMAGE:figures/full_fig_p011_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: Rotating symmetric dyon (𝑚 = 0.5, 𝑛 = 0.05, 𝑞 = 𝑝 = 0.07, 𝑎 = 0.492). The most sophisticated pattern presenting all types of hair in both sectors. 11 [PITH_FULL_IMAGE:figures/full_fig_p011_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: 𝑚 = 0.15, 𝑛 = 2, 𝑞 = 1.81, 𝑝 = 0.1, 𝑎 = 0. No electric separatrix and all the electric LFs propagate to infinity, though the MD strings magnetic charge densities change sign, so all magnetic LFs are confined (SS and SH hair). 13 [PITH_FULL_IMAGE:figures/full_fig_p013_14.png] view at source ↗
Figure 15
Figure 15. Figure 15: 𝑚 = 0.44, 𝑛 = 0.01, 𝑞 = 0.2, 𝑝 = 0, 𝑎 = 0.343. Electric panel: oppositely charged strings and positive horizon. Magnetic charge density of the horizon changes sign, so both SH and HH hair are present [PITH_FULL_IMAGE:figures/full_fig_p014_15.png] view at source ↗
Figure 16
Figure 16. Figure 16: 𝑚 = 2, 𝑛 = 0.16, 𝑞 = 0.42, 𝑝 = −1, 𝑎 = 1.5. SH and HH electric hair, SH magnetic hair [PITH_FULL_IMAGE:figures/full_fig_p014_16.png] view at source ↗
Figure 17
Figure 17. Figure 17: 𝑚 = 0.5, 𝑛 = 0.5, 𝑞 = 0.07, 𝑝 = 0.07, 𝑎 = 0.7. Electric HH hair and both SS and SH hair. 14 [PITH_FULL_IMAGE:figures/full_fig_p014_17.png] view at source ↗
read the original abstract

We uncover the physical nature of the electric and magnetic monopoles discovered by McGuire and Ruffini on Misner strings accompanying charged nutty black holes, showing that these strings carry singular, nonuniform flows of electric and magnetic fields. These fields inevitably have nonzero divergence, thereby simulating the effective electric and magnetic charge densities along the strings. The latter create a complex short-range electromagnetic hair zone around the horizon, making the combined Misner-Dirac strings classically observable. Typical features of this new type of hair are presented. We also note that rotation can act as a hair generator even in the absence of NUT.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The paper claims that the electric and magnetic monopoles previously identified by McGuire and Ruffini on Misner strings in charged nutty black holes arise from singular nonuniform flows of the electric and magnetic fields. These flows possess nonzero divergence that simulates effective electric and magnetic charge densities along the strings, thereby generating a complex short-range electromagnetic hair zone around the horizon and rendering the combined Misner-Dirac strings classically observable. The manuscript also notes that rotation can generate such hair even in the absence of the NUT parameter.

Significance. If the central interpretation is rigorously established, the result would provide a concrete physical mechanism for electromagnetic hair in NUT-charged spacetimes, potentially clarifying the observability of Misner strings and extending no-hair considerations to include distributional sources. The additional observation on rotation as a hair generator broadens the scope beyond the NUT sector and could motivate further studies of rotating solutions with effective charges.

major comments (2)
  1. [Abstract / field-flow discussion] Abstract and main discussion of field flows: the assertion that singular nonuniform E/B flows produce nonzero divergence that can be read directly as physical charge densities creating a short-range hair zone is load-bearing for the hair claim, yet the manuscript provides no explicit distributional regularization (e.g., delta-function contributions to the Maxwell equations or a limiting smoothing procedure) of the stress-energy tensor along the Misner strings. Without this step it remains unclear whether the simulated densities are physical sources or removable coordinate artifacts.
  2. [Rotation hair note] Section on rotation as hair generator: the statement that rotation can act as a hair generator even without NUT is presented without an explicit metric ansatz, field configuration, or calculation showing the induced divergence or effective charge density, making it difficult to assess whether this extends the main result or remains conjectural.
minor comments (1)
  1. [Hair zone description] Notation for the 'complex short-range electromagnetic hair zone' is introduced without a precise definition or radial profile, which could be clarified by adding a brief equation or plot of the effective charge density fall-off.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading of our manuscript and the constructive comments, which help to strengthen the presentation of our results on the electromagnetic hair of charged nutty black holes. We respond to each major comment below, indicating the revisions we will incorporate.

read point-by-point responses
  1. Referee: [Abstract / field-flow discussion] Abstract and main discussion of field flows: the assertion that singular nonuniform E/B flows produce nonzero divergence that can be read directly as physical charge densities creating a short-range hair zone is load-bearing for the hair claim, yet the manuscript provides no explicit distributional regularization (e.g., delta-function contributions to the Maxwell equations or a limiting smoothing procedure) of the stress-energy tensor along the Misner strings. Without this step it remains unclear whether the simulated densities are physical sources or removable coordinate artifacts.

    Authors: We agree that an explicit distributional regularization would make the physical nature of the effective charges more rigorous. In the revised manuscript we will add a dedicated subsection that regularizes the singular field flows along the Misner strings, explicitly computing the delta-function contributions to the Maxwell equations and confirming that the nonzero divergences correspond to physical charge densities rather than coordinate artifacts. This addition will directly support the short-range hair interpretation. revision: yes

  2. Referee: [Rotation hair note] Section on rotation as hair generator: the statement that rotation can act as a hair generator even without NUT is presented without an explicit metric ansatz, field configuration, or calculation showing the induced divergence or effective charge density, making it difficult to assess whether this extends the main result or remains conjectural.

    Authors: The remark on rotation is offered as a brief extension based on the structure of the electromagnetic field in rotating spacetimes. To address the concern, we will expand the note into a short explicit example in the revised version, using the Kerr-Newman metric (which has no NUT parameter) and computing the divergence of the electromagnetic fields along the axis to exhibit the induced effective charge density. This will demonstrate that the mechanism is not limited to the NUT sector. revision: yes

Circularity Check

0 steps flagged

No significant circularity in the derivation chain

full rationale

The paper interprets the electric and magnetic monopoles on Misner strings (previously identified by McGuire and Ruffini) as arising from singular nonuniform flows of E and B fields whose classical divergence simulates effective charge densities, creating short-range hair. This interpretive step applies standard Maxwell equations to the known charged NUT solution without fitting parameters to data, without renaming a known result as new, and without load-bearing self-citations or uniqueness theorems imported from the authors' prior work. The central claim does not reduce by construction to its own inputs; the divergence is computed directly from the metric and field ansatz of the existing solution. No self-definitional loops or fitted-input predictions are present.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The abstract invokes standard classical general relativity and Maxwell theory on a fixed background metric; no free parameters, ad-hoc axioms, or new entities are introduced in the provided text.

axioms (1)
  • standard math Classical general relativity and Maxwell electromagnetism hold for the nutty black-hole metrics.
    The interpretation of field divergence as charge density presupposes the validity of the Einstein-Maxwell equations in curved spacetime.

pith-pipeline@v0.9.0 · 5389 in / 1183 out tokens · 27890 ms · 2026-05-16T09:02:00.052114+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 1 Pith paper

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

  1. Gravielectric and gravimagnetic fluxes in nutty black holes

    gr-qc 2026-05 unverdicted novelty 6.0

    Misner strings carry singular gravielectric and gravimagnetic fluxes that connect horizons to infinity, explaining negative Komar masses as incoming field lines and showing the strings are massless empty tubes.

Reference graph

Works this paper leans on

32 extracted references · 32 canonical work pages · cited by 1 Pith paper · 7 internal anchors

  1. [1]

    Empty space generalization of the Schwarzschild met- ric,

    E. Newman, L. Tamburino and T. Unti, “Empty space generalization of the Schwarzschild met- ric,” J. Math. Phys.4, 915 (1963)

  2. [2]

    The Flatter regions of Newman, Unti and Tamburino’s generalized Schwarzschild space,

    C. W. Misner, “The Flatter regions of Newman, Unti and Tamburino’s generalized Schwarzschild space,” J. Math. Phys.4, 924-938 (1963)

  3. [3]

    Electromagnetic Fields in a Homogeneous, Nonisotropic Universe

    D.R. Brill, “Electromagnetic Fields in a Homogeneous, Nonisotropic Universe”, Phys. Rev.133, B845 (1964)

  4. [4]

    Rehabilitating space-times with NUTs

    G. Cl´ ement, D. Gal’tsov and M. Guenouche, “Rehabilitating space-times with NUTs,” Phys. Lett. B750, 591-594 (2015) [arXiv:1508.07622 [hep-th]]

  5. [5]

    NUT wormholes

    G. Cl´ ement, D. Gal’tsov and M. Guenouche, “NUT wormholes,” Phys. Rev. D93, no.2, 024048 (2016) [arXiv:1509.07854 [hep-th]]

  6. [6]

    Motion of charged particles in a NUTty Einstein-Maxwell spacetime and causality violation,

    G. Cl´ ement and M. Guenouche, “Motion of charged particles in a NUTty Einstein-Maxwell spacetime and causality violation,” Gen. Rel. Grav.50, no.6, 60 (2018) [arXiv:1606.08457 [gr- qc]]

  7. [7]

    A new interpretation of the NUT metric in general relativity,

    W. B. Bonnor, “A new interpretation of the NUT metric in general relativity,” Math. Proc. Cambridge Phil. Soc.66, no.1, 145-151 (1969)

  8. [8]

    Physical interpretation of N.U.T

    Sackfield A. Physical interpretation of N.U.T. metric. Mathematical Proceedings of the Cam- bridge Philosophical Society. 1971;70(1):89-94

  9. [9]

    Thermodynamics and Phase Transitions of NUTty Dyons

    A. B. Bordo, F. Gray and D. Kubizˇ n´ ak, “Thermodynamics and Phase Transitions of NUTty Dyons,” JHEP07, 119 (2019) [arXiv:1904.00030 [hep-th]]

  10. [10]

    Thermodynamics of Lorentzian Taub-NUT spacetimes,

    R. A. Hennigar, D. Kubizˇ n´ ak and R. B. Mann, “Thermodynamics of Lorentzian Taub-NUT spacetimes,” Phys. Rev. D100, no.6, 064055 (2019) [arXiv:1903.08668 [hep-th]]

  11. [11]

    The First Law for Rotating NUTs,

    A. Ballon Bordo, F. Gray, R. A. Hennigar and D. Kubizˇ n´ ak, “The First Law for Rotating NUTs,” Phys. Lett. B798, 134972 (2019) [arXiv:1905.06350 [hep-th]]

  12. [12]

    The first law of black hole thermodynamics for Taub–NUT spacetime,

    R. Durka, “The first law of black hole thermodynamics for Taub–NUT spacetime,” Int. J. Mod. Phys. D31, no.04, 2250021 (2022) [arXiv:1908.04238 [gr-qc]]

  13. [13]

    Thermodynamical hairs of the four-dimensional Taub-Newman-Unti- Tamburino spacetimes,

    S. Q. Wu and D. Wu, “Thermodynamical hairs of the four-dimensional Taub-Newman-Unti- Tamburino spacetimes,” Phys. Rev. D100, no.10, 101501 (2019) [arXiv:1909.07776 [hep-th]]

  14. [14]

    Classical physics as geometry: Gravitation, electromagnetism, unquantized charge, and mass as properties of curved empty space,

    C. W. Misner and J. A. Wheeler, “Classical physics as geometry: Gravitation, electromagnetism, unquantized charge, and mass as properties of curved empty space,” Annals Phys.2, 525-603 (1957). 15

  15. [15]

    Some Magnetic and Electric Monopole One-Body Solutions of the Maxwell-Einstein Equations,

    P. Mcguire and R. Ruffini, “Some Magnetic and Electric Monopole One-Body Solutions of the Maxwell-Einstein Equations,” Phys. Rev. D12, 3019-3025 (1975)

  16. [16]

    On the Smarr formula for rotating dyonic black holes

    G. Cl´ ement and D. Gal’tsov, “On the Smarr formula for rotating dyonic black holes,” Phys. Lett. B773, 290-294 (2017) [arXiv:1707.01332 [gr-qc]]

  17. [17]

    On the Smarr formulas for electrovac spacetimes with line singu- larities,

    G. Cl´ ement and D. Gal’tsov, “On the Smarr formulas for electrovac spacetimes with line singu- larities,” Phys. Lett. B802, 135270 (2020) [arXiv:1908.10617 [gr-qc]]

  18. [18]

    Thermodynamics of Rotating NUTty Dyons,

    A. Ballon Bordo, F. Gray and D. Kubizˇ n´ ak, “Thermodynamics of Rotating NUTty Dyons,” JHEP05, 084 (2020) [arXiv:2003.02268 [hep-th]]

  19. [19]

    Thermodynamics of Dyonic NUT Charged Black Holes with entropy as Noether charge,

    N. Abbasvandi, M. Tavakoli and R. B. Mann, “Thermodynamics of Dyonic NUT Charged Black Holes with entropy as Noether charge,” JHEP08, 152 (2021) [arXiv:2107.00182 [hep-th]]

  20. [20]

    Lorentzian Taub-NUT spacetimes: Misner string charges and the first law,

    A. Awad and S. Eissa, “Lorentzian Taub-NUT spacetimes: Misner string charges and the first law,” Phys. Rev. D105, no.12, 124034 (2022) [arXiv:2206.09124 [hep-th]]

  21. [21]

    Quantized singularities in the electromagnetic field,,

    P. A. M. Dirac, “Quantized singularities in the electromagnetic field,,” Proc. Roy. Soc. Lond. A 133, no.821, 60-72 (1931)

  22. [22]

    Rotating traversable wormholes in Einstein-Maxwell theory,

    G. Cl´ ement and D. Gal’tsov, “Rotating traversable wormholes in Einstein-Maxwell theory,” Phys. Lett. B838, 137677 (2023) [arXiv:2210.08913 [gr-qc]]

  23. [23]

    Magnetic monopole field exposed by electrons

    A. B´ ech´ e, R. Van Boxem, G. Van Tendeloo and J. Verbeeck, “Magnetic monopole field exposed by electrons,” Nature Phys.10, 26-29 (2014) [arXiv:1305.0570 [physics.ins-det]]

  24. [24]

    Significance of electromagnetic potentials in the quantum theory,

    Y. Aharonov and D. Bohm, “Significance of electromagnetic potentials in the quantum theory,” Phys. Rev.115, 485-491 (1959)

  25. [25]

    Angular Momentum Paradoxes with Solenoids and Monopoles,

    H. J. Lipkin and M. Peshkin, “Angular Momentum Paradoxes with Solenoids and Monopoles,” Phys. Lett. B118, 385 (1982)

  26. [26]

    Gravitating Non-Abelian Solitons and Black Holes with Yang-Mills Fields

    M. S. Volkov and D. V. Gal’tsov, “Gravitating nonAbelian solitons and black holes with Yang- Mills fields,” Phys. Rept.319, 1-83 (1999) [arXiv:hep-th/9810070 [hep-th]]

  27. [27]

    A note on the calculation of the Komar integral in the Lorentzian Taub-NUT spacetime,

    G. Barbagallo, J. L. V. Cerdeira, C. G´ omez-Fayr´ en and T. Ort´ ın, “A note on the calculation of the Komar integral in the Lorentzian Taub-NUT spacetime,” [arXiv:2505.15349 [gr-qc]]

  28. [28]

    BLACK HOLES: THE MEMBRANE PARADIGM,

    K. S. Thorne, R. H. Price and D. A. Macdonald, Eds. “BLACK HOLES: THE MEMBRANE PARADIGM,” Yale University Prees, New Heaven and London, 1986

  29. [29]

    Christodoulou and R

    D. Christodoulou and R. Ruffini, inBlack Holes, edited by B. DeWitt and C. DeWitt(Gordon and Breach, New York, 1973)

  30. [30]

    Lines of Force of a Point Charge near a Schwarzschild Black Hole,

    R. S. Hanni and R. Ruffini, “Lines of Force of a Point Charge near a Schwarzschild Black Hole,” 16 Phys. Rev. D8, 3259-3265 (1973)

  31. [31]

    Ehlers--Harrison--Type Transformations in Dilaton--Axion Gravity

    D. V. Galtsov and O. V. Kechkin, “Ehlers-Harrison type transformations in dilaton - axion gravity,” Phys. Rev. D50(1994), 7394-7399. [arXiv:hep-th/9407155 [hep-th]]

  32. [32]

    Gauged supergravities: Solutions with a Killing tensor,

    D. Gal’tsov and R. Karsanov, “Gauged supergravities: Solutions with a Killing tensor,” Phys. Rev. D111, no.10, 104011 (2025) [arXiv:2503.06589 [gr-qc]]. 17