Charged Black Holes in Quasi-Topological Gravity Coupled to Born-Infeld Nonlinear Electrodynamics
Pith reviewed 2026-05-21 10:00 UTC · model grok-4.3
The pith
In quasi-topological gravity coupled to Born-Infeld electrodynamics, some models produce charged black holes with interior curvature singularities while others keep them regular.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We construct static, spherically symmetric black hole solutions in quasi-topological gravity coupled to Born-Infeld nonlinear electrodynamics. Starting from the spherically reduced action, we derive closed-form expressions for the electric field, the nonlinear Lagrangian, and the metric function involving hypergeometric functions. We consider specific versions of QTG in which vacuum black holes are regular, and show that for some of these models charged black holes develop a curvature singularity at a finite radius in their interior. In contrast, in models such as a Born-Infeld-type QTG, charged black holes remain regular, though the de Sitter core is replaced by an anti-de Sitter core.
What carries the argument
The spherically reduced action of quasi-topological gravity coupled to Born-Infeld electrodynamics, yielding metric functions expressed with hypergeometric functions that determine the regularity properties.
If this is right
- Charged black holes in some QTG models develop curvature singularities at finite interior radii.
- Born-Infeld-type QTG models maintain regularity for charged black holes.
- The core of regular charged solutions is anti-de Sitter rather than de Sitter.
- Several limiting regimes of these black hole solutions can be analyzed explicitly.
Where Pith is reading between the lines
- This indicates that the specific form of the quasi-topological terms can be chosen to avoid singularities in charged cases.
- Similar nonlinear electrodynamics couplings could be tested in other higher-curvature gravity theories for regular black hole constructions.
- The change to an anti-de Sitter core may affect the causal structure or thermodynamic properties of the black holes.
Load-bearing premise
The analysis assumes specific versions of quasi-topological gravity where the vacuum black holes are regular.
What would settle it
Computing the curvature invariants such as the Kretschmann scalar from the derived metric function and checking whether they diverge at a finite radius for charged solutions in the non-Born-Infeld models.
Figures
read the original abstract
We construct static, spherically symmetric black hole solutions in quasi-topological gravity (QTG) coupled to Born-Infeld nonlinear electrodynamics. Starting from the spherically reduced action, we derive closed-form expressions for the electric field, the nonlinear Lagrangian, and the metric function, the latter involving hypergeometric functions. We consider specific versions of QTG in which vacuum black holes are regular, and show that, for some of these models, charged black holes develop a curvature singularity at a finite radius in their interior. In contrast, in models such as a Born-Infeld-type QTG, charged black holes remain regular. In this case, however, the de Sitter core of the neutral solution is replaced by an anti-de Sitter core. We also discuss several limiting regimes of these solutions.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript constructs static, spherically symmetric black hole solutions in quasi-topological gravity (QTG) coupled to Born-Infeld nonlinear electrodynamics. Starting from the spherically reduced action, closed-form expressions are obtained for the electric field, the nonlinear Lagrangian, and the metric function (involving hypergeometric functions). Specific QTG models that yield regular vacuum black holes are examined; the authors show that charged solutions in some of these models develop a curvature singularity at finite interior radius, while a Born-Infeld-type QTG model remains regular, albeit with an anti-de Sitter core replacing the de Sitter core of the neutral solution. Limiting regimes are also discussed.
Significance. If the explicit derivations hold, the work supplies analytic black-hole solutions in a higher-curvature gravity theory coupled to nonlinear electrodynamics. The ability to distinguish, via closed-form expressions, between models that acquire interior singularities upon charging and those that remain regular (with an AdS core) offers concrete insight into how nonlinear electrodynamics modifies interior structure in quasi-topological gravity. The hypergeometric representation of the metric function is a technical strength that permits direct examination of curvature invariants without numerical integration.
major comments (1)
- [§4 (regularity analysis)] The central regularity claims rest on the explicit hypergeometric metric functions derived from the reduced action. The manuscript should supply a direct verification (e.g., asymptotic expansion or plot of the Kretschmann scalar) that a curvature singularity indeed appears at finite radius for the models discussed after Eq. (the electric-field solution), rather than relying solely on the formal expression.
minor comments (2)
- [Abstract] The abstract states that vacuum black holes are regular for the chosen QTG models; a brief reminder of the vacuum metric function (or reference to the appropriate earlier equation) would help readers connect the charged and neutral cases.
- [Metric-function derivation] Notation for the hypergeometric parameters appearing in the metric function should be defined explicitly when first introduced, to avoid ambiguity when taking the various limiting regimes mentioned in the final section.
Simulated Author's Rebuttal
We thank the referee for the positive assessment of our manuscript on charged black hole solutions in quasi-topological gravity coupled to Born-Infeld electrodynamics. The suggestion for explicit verification of the curvature singularity is constructive, and we address it below.
read point-by-point responses
-
Referee: [§4 (regularity analysis)] The central regularity claims rest on the explicit hypergeometric metric functions derived from the reduced action. The manuscript should supply a direct verification (e.g., asymptotic expansion or plot of the Kretschmann scalar) that a curvature singularity indeed appears at finite radius for the models discussed after Eq. (the electric-field solution), rather than relying solely on the formal expression.
Authors: We agree that an explicit verification strengthens the presentation of the regularity analysis. Although the closed-form hypergeometric metric function allows direct analytic computation of curvature invariants, we will add in the revised manuscript an asymptotic expansion of the Kretschmann scalar approaching the finite interior radius for the models that develop singularities. This expansion will confirm the divergence without relying only on the formal expression, while leaving the core derivations and conclusions unchanged. revision: yes
Circularity Check
No significant circularity; derivation is self-contained from the action
full rationale
The paper begins with the spherically reduced action for quasi-topological gravity coupled to Born-Infeld nonlinear electrodynamics and derives closed-form expressions for the electric field, nonlinear Lagrangian, and metric function (involving hypergeometric functions) directly from the equations of motion. Regularity properties for charged solutions in selected models (including those regular in vacuum) are then analyzed from these explicit expressions, with distinctions such as interior singularities versus AdS cores following from the solutions themselves. No load-bearing step reduces by construction to a fitted input, self-definition, or unverified self-citation chain; the construction remains independent of the target results.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption Specific versions of quasi-topological gravity admit regular vacuum black holes
Lean theorems connected to this paper
-
IndisputableMonolith/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
We construct static, spherically symmetric black hole solutions in quasi-topological gravity (QTG) coupled to Born-Infeld nonlinear electrodynamics. Starting from the spherically reduced action, we derive closed-form expressions for the electric field, the nonlinear Lagrangian, and the metric function, the latter involving hypergeometric functions.
-
IndisputableMonolith/Foundation/RealityFromDistinction.leanreality_from_one_distinction unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
In the presence of charge, Hayward-type black holes can develop a curvature singularity at a finite radius within their interior, whereas Born–Infeld-type solutions remain regular for all values of the parameters.
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Forward citations
Cited by 3 Pith papers
-
Cosmologically viable non-polynomial quasi-topological gravity: explicit models, $\Lambda$CDM limit and observational constraints
Non-polynomial quasi-topological gravity models reproduce the standard thermal history, generate dynamical dark energy of geometric origin, and fit supernova, cosmic chronometer, and BAO data competitively with ΛCDM.
-
All $2D$ generalised dilaton theories from $d\geq 4$ gravities
Generic 2D Horndeski theories arise from dimensional reduction of d≥4 gravities, yielding a Birkhoff theorem for quasi-topological gravities where static spherically symmetric solutions satisfy g_tt g_rr = -1 and are ...
-
$g_{tt}g_{rr} =-1$ black hole thermodynamics in extended quasi-topological gravity
A unified framework links the generating function for static black holes satisfying g_tt g_rr=-1 in extended quasi-topological gravity to thermodynamic mass and Wald entropy via an effective 2D dilaton theory.
Reference graph
Works this paper leans on
-
[1]
Uncharged vacuum black holes in the Hayward-type QTG Using expression (6.10) and considering ˆQ= 0, one gets p= µ rD−1 +ℓ 2µ .(6.13) Atr→ ∞one has thatp∼ µ rD−1 , while atr= 0 the curvature invariant goes to the constant valuep=p 0 = 1/ℓ2. The equationf= 0 gives rD−1 =µ(r 2 −ℓ 2).(6.14) Condition (6.14) determines the locations of the horizons. There exis...
-
[2]
Uncharged vacuum black holes in the Born-Infeld-type QTG Using expression (6.10) and setting ˆQ= 0, one gets p= µp r2(D−2) +ℓ 4µ2 .(6.19) The equation defining the horizons,f= 0 gives −µr2 + p r2(D−1) +ℓ 4µ2 = 0.(6.20) The second condition,d f /dr= 0, gives r2D−2 = 2ℓ4µ2 D−3 .(6.21) Using this condition in (6.20), one can solve for the crit- ical dimensio...
-
[3]
C. W. Misner, K. S. Thorne, and J. A. Wheeler,Gravi- tation(W. H. Freeman, San Francisco, 1973)
work page 1973
-
[4]
J. M. Bardeen, Non-singular general-relativistic gravita- tional collapse, inProceedings of the 5th International Conference on Gravitation and the Theory of Relativity (GR5), Vol. 174 (Tbilisi, 1968)
work page 1968
-
[5]
E. Ay´ on-Beato and A. Garcia, The bardeen model as a nonlinear magnetic monopole, Physics Letters B493, 149 (2000)
work page 2000
-
[6]
V. P. Frolov and G. A. Vilkovisky, Spherically Symmetric Collapse in Quantum Gravity, Phys. Lett. B106, 307 (1981)
work page 1981
-
[7]
E. B. Gliner, Algebraic Properties of the Energy- momentum Tensor and Vacuum-like States of Matter, Sov. Phys. JETP22, 378 (1966)
work page 1966
-
[8]
Dymnikova, Vacuum nonsingular black hole, Gen
I. Dymnikova, Vacuum nonsingular black hole, Gen. Rel. Grav.24, 235 (1992)
work page 1992
-
[9]
Dymnikova, The cosmological term as a source of mass, Classical and Quantum Gravity19, 725 (2002)
I. Dymnikova, The cosmological term as a source of mass, Classical and Quantum Gravity19, 725 (2002)
work page 2002
-
[10]
I. Dymnikova, Regular electrically charged vacuum struc- tures with de sitter centre in nonlinear electrodynam- ics coupled to general relativity, Classical and Quantum Gravity21, 4417 (2004)
work page 2004
-
[11]
V. P. Frolov, M. A. Markov, and V. F. Mukhanov, Through a black hole into a new universe?, Phys. Lett. B216, 272 (1989)
work page 1989
-
[12]
V. P. Frolov, M. A. Markov, and V. F. Mukhanov, Black Holes as Possible Sources of Closed and Semiclosed Worlds, Phys. Rev. D41, 383 (1990)
work page 1990
-
[13]
How Many New Worlds Are Inside a Black Hole?
C. Barrabes and V. P. Frolov, How many new worlds are inside a black hole?, Phys. Rev. D53, 3215 (1996), arXiv:hep-th/9511136
work page internal anchor Pith review Pith/arXiv arXiv 1996
-
[14]
S. A. Hayward, Formation and evaporation of nonsingu- lar black holes, Phys. Rev. Lett.96, 031103 (2006)
work page 2006
-
[15]
V. P. Frolov, Notes on nonsingular models of black holes, Phys. Rev. D94, 104056 (2016)
work page 2016
-
[16]
A. Simpson and M. Visser, Regular black holes with asymptotically minkowski cores, Universe6(2020)
work page 2020
- [17]
-
[18]
J. P. S. Lemos and P. M. S´ a, Black holes of a general two-dimensional dilaton gravity theory, Phys. Rev. D49, 2897 (1994)
work page 1994
-
[19]
J. Barenboim, A. V. Frolov, and G. Kunstatter, No drama in two-dimensional black hole evaporation, Phys. Rev. Res.6, L032055 (2024)
work page 2024
-
[20]
J. Barenboim, A. V. Frolov, and G. Kunstatter, Evapo- ration of regular black holes in 2d dilaton gravity, Phys. Rev. D111, 104068 (2025)
work page 2025
-
[22]
A. Coll´ eaux, S. Chinaglia, and S. Zerbini, Nonpolynomial lagrangian approach to regular black holes, International 16 Journal of Modern Physics D27, 1830002 (2018)
work page 2018
-
[23]
R. Carballo-Rubio, F. D. Filippo, S. Liberati, M. Visser, J. Arrechea, C. Barcel´ o, A. Bonanno, J. Borissova, V. Boyanov, V. Cardoso, F. D. Porro, A. Eichhorn, D. Jampolski, P. Mart´ ın-Moruno, J. Mazza, T. Mc- Maken, A. Panassiti, P. Pani, A. Platania, L. Rezzolla, and V. Vellucci, Towards a non-singular paradigm of black hole physics, Journal of Cosmol...
-
[24]
C. Bambi, ed.,Regular Black Holes: Towards a New Paradigm of Gravitational Collapse, Springer Series in Astrophysics and Cosmology (Springer Singapore, 2023)
work page 2023
-
[25]
C. Lan, H. Yang, Y. Guo, and Y.-G. Miao, Regular black holes: A short topic review, International Journal of The- oretical Physics62, 202 (2023)
work page 2023
-
[26]
P. Bueno, P. A. Cano, and R. A. Hennigar, (generalized) quasi-topological gravities at all orders, Classical and Quantum Gravity37, 015002 (2019), arXiv:1909.07983 [hep-th]
- [27]
- [28]
-
[29]
J. Oliva and S. Ray, A new cubic theory of gravity in five dimensions: black hole, birkhoff’s theorem and c-function, Classical and Quantum Gravity27, 225002 (2010)
work page 2010
-
[30]
R. A. Hennigar, D. Kubizˇ n´ ak, and R. B. Mann, Gener- alized quasitopological gravity, Phys. Rev. D95, 104042 (2017), arXiv:1703.01631 [hep-th]
work page internal anchor Pith review Pith/arXiv arXiv 2017
-
[31]
R. C. Myers and B. Robinson, Black Holes in Quasi- topological Gravity, JHEP08, 067, arXiv:1003.5357 [gr- qc]
work page internal anchor Pith review Pith/arXiv arXiv
-
[32]
J. Moreno and A. J. Murcia, Classification of general- ized quasitopological gravities, Phys. Rev. D108, 044016 (2023), arXiv:2304.08510 [gr-qc]
- [33]
-
[34]
V. P. Frolov, A. Koek, J. P. Soto, and A. Zelnikov, Regu- lar black holes inspired by quasitopological gravity, Phys. Rev. D111, 044034 (2025)
work page 2025
- [35]
-
[36]
P. Bueno, R. A. Hennigar, ´Angel J. Murcia, and A. Vicente-Cano, Buchdahl limits in theories with reg- ular black holes (2026), arXiv:2512.19796 [gr-qc]
-
[37]
P. Bueno, P. A. Cano, R. A. Hennigar, and ´A. J. Murcia, Regular black hole formation in four-dimensional non- polynomial gravities, Phys. Rev. D113, 024019 (2026), arXiv:2509.19016 [gr-qc]
- [38]
- [39]
-
[40]
Cosmic Inflation From Regular Black Holes
K. Sueto, R. Yoshimoto, and P. A. Cano, Cosmic Infla- tion From Regular Black Holes (2026), arXiv:2604.04601 [gr-qc]
work page internal anchor Pith review Pith/arXiv arXiv 2026
-
[41]
A. Bonanno, A. Panassiti, and F. Saueressig, Cauchy horizon (in)stability of regular black holes (2025), arXiv:2507.03581 [gr-qc]
-
[42]
E. Poisson and W. Israel, Inner-horizon instability and mass inflation in black holes, Phys. Rev. Lett.63, 1663 (1989)
work page 1989
-
[43]
E. Poisson and W. Israel, Internal structure of black holes, Phys. Rev. D41, 1796 (1990)
work page 1990
-
[44]
Ori, Inner structure of a charged black hole: An exact mass-inflation solution, Phys
A. Ori, Inner structure of a charged black hole: An exact mass-inflation solution, Phys. Rev. Lett.67, 789 (1991)
work page 1991
-
[45]
V. P. Frolov and A. Zelnikov, Regular black holes in quasitopological gravity: Null shells and mass inflation (2026), arXiv:2601.01861 [gr-qc]
work page internal anchor Pith review Pith/arXiv arXiv 2026
- [46]
- [47]
-
[48]
D. P. Sorokin, Introductory notes on non-linear electro- dynamics and its applications, Fortschritte der Physik 70, 2200092 (2022)
work page 2022
-
[49]
A. Bokuli´ c, I. Smoli´ c, and T. Juri´ c, Constraints on sin- gularity resolution by nonlinear electrodynamics, Phys. Rev. D106, 064020 (2022)
work page 2022
-
[50]
E. Ayon-Beato and A. Garcia, Regular black hole in general relativity coupled to nonlinear electrodynamics, Phys. Rev. Lett.80, 5056 (1998)
work page 1998
-
[51]
K. A. Bronnikov, Regular magnetic black holes and monopoles from nonlinear electrodynamics, Phys. Rev. D63, 044005 (2001)
work page 2001
-
[52]
M. E. Fels and C. G. Torre, The Principle of symmetric criticality in general relativity, Class. Quant. Grav.19, 641 (2002), arXiv:gr-qc/0108033
work page internal anchor Pith review Pith/arXiv arXiv 2002
-
[53]
I. M. Anderson, M. E. Fels, and C. G. Torre, Group Invariant Solutions Without Transversality, Commun. Math. Phys.212, 653 (2000), arXiv:math-ph/9910015
work page internal anchor Pith review Pith/arXiv arXiv 2000
-
[54]
H. Kodama and A. Ishibashi, Master equations for per- turbations of generalized static black holes with charge in higher dimensions, Prog. Theor. Phys.111, 29 (2004), arXiv:hep-th/0308128
work page internal anchor Pith review Pith/arXiv arXiv 2004
-
[55]
F. W. J. Olver, D. W. Lozier, R. F. Boisvert, and C. W. Clark,The NIST Handbook of Mathematical Functions (Cambridge University Press, New York, NY, 2010)
work page 2010
-
[56]
A. Garcia D., H. Salazar I., and J. F. Plebanski, Type- d solutions of the einstein and born-infeld nonlinear- electrodynamics equations, Il Nuovo Cimento B (1971- 1996)84, 65 (1984)
work page 1971
-
[57]
S. Fernando and D. Krug, Letter: Charged black hole solutions in einstein–born–infeld gravity with a cosmo- logical constant, General Relativity and Gravitation35, 129 (2003)
work page 2003
-
[58]
H. P. de Oliveira, Non-linear charged black holes, Classi- cal and Quantum Gravity11, 1469 (1994)
work page 1994
- [59]
-
[60]
T. Kumar Dey, Born–infeld black holes in the presence of a cosmological constant, Physics Letters B595, 484 (2004)
work page 2004
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.