Energy Conditions and Stability of Charged Wormholes in f(R, mathscr{L}_m) Gravity: A Comparative Analysis with Compact Objects
Pith reviewed 2026-05-23 00:10 UTC · model grok-4.3
The pith
Charged wormholes in f(R, L_m) gravity satisfy radial null energy condition over wide charge ranges but tangential condition only for 0.1 to 0.6, enabling stable throat structures.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
Our findings show that the radial NEC remains satisfied across a wide range of charge parameters E consistent with established physical laws. However, the tangential NEC is only sustained in the range 0.1 ≤ E ≤ 0.6; for higher charge values, violations occur, indicating the formation of a throat-like structure necessary for wormhole stability. Additionally, we compare the pressure-density profiles of these charged wormholes with those of compact objects such as neutron stars, revealing distinct variations in matter distribution.
What carries the argument
The Exponential Spheroid shape function together with two explicit forms of the charge function E^2, used to obtain energy density and pressure expressions and test the null energy conditions in the f(R, L_m) framework.
If this is right
- Radial null energy condition holds for many physically allowed charge values.
- Tangential null energy condition restricts to the interval 0.1 to 0.6.
- Violations of the tangential condition at higher charge values signal the throat structure required for stability.
- Pressure-density profiles differ from those of neutron stars, indicating distinct matter distributions.
- Charge parameter and the modified gravity framework together control wormhole stability characteristics.
Where Pith is reading between the lines
- Charge values could be tuned to produce stable wormhole solutions within this class of modified gravity theories.
- The distinction in matter profiles from neutron stars suggests possible observational signatures that separate wormholes from compact stars.
- Similar charge-dependent behavior might appear when the same analysis is repeated in other modified gravity models.
- The qualitative role of charge in controlling throat formation may survive changes to the shape function.
- wormholes
- energy conditions
- modified gravity
- null energy condition
Load-bearing premise
The reported ranges for satisfaction of the null energy conditions rest on the specific Exponential Spheroid shape function, the chosen forms of E^2, and one fixed but unspecified version of f(R, L_m); altering any of these modeling choices would shift the ranges.
What would settle it
Explicit computation of the tangential null energy condition for the Exponential Spheroid model at charge value E=0.7, checking whether it is violated as predicted while the radial condition remains satisfied.
Figures
read the original abstract
In this paper, we study the energy conditions of charged traversable wormholes in the framework of $f(R, \mathscr{L}_m)$ modified gravity. In the first case, we derive the shape functions (SFs) for two different choices of the charge function $\mathcal{E}^2$ by considering the Exponential Spheroid (ES) model and analyze the null energy condition (NEC). In the second case, we consider a particular shape function and study its implications for the energy conditions. In both cases, we obtain expressions for energy density and pressure in radial and tangential directions. Our findings show that the radial NEC remains satisfied across a wide range of charge parameters $\mathcal{E}$ consistent with established physical laws. However, the tangential NEC is only sustained in the range $0.1 \leq \mathcal{E} \leq 0.6$; for higher charge values, violations occur, indicating the formation of a throat-like structure necessary for wormhole stability. Additionally, we compare the pressure-density profiles of these charged wormholes with those of compact objects such as neutron stars, revealing distinct variations in matter distribution. This analysis highlights the crucial role of charge and modified gravity in determining the stability and physical characteristics of wormhole structures.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper studies energy conditions of charged traversable wormholes in f(R, ℒ_m) gravity. In the first case, shape functions are derived for two choices of charge function ℰ² using the Exponential Spheroid model and null energy conditions (NEC) are analyzed. In the second case, a particular shape function is considered. Expressions for energy density and radial/tangential pressures are obtained. The central claim is that radial NEC holds across a wide range of charge parameter ℰ consistent with physical laws, while tangential NEC holds only for 0.1 ≤ ℰ ≤ 0.6; violations at higher ℰ indicate throat-like structure for stability. Pressure-density profiles are compared to those of compact objects such as neutron stars.
Significance. If the results hold, the work illustrates how the charge parameter and modified gravity affect the satisfaction of energy conditions in wormhole spacetimes and provides a comparison of matter profiles with those of neutron stars, potentially aiding in distinguishing wormhole candidates from compact objects.
major comments (3)
- [Abstract] Abstract: the headline result that tangential NEC holds only for 0.1 ≤ ℰ ≤ 0.6 (with violations at higher values indicating throat structure) is obtained by direct substitution of the Exponential Spheroid shape function and the two chosen ℰ² forms into the modified field equations; the paper provides no demonstration that this specific interval survives for other shape functions obeying the flaring-out conditions b(r₀)=r₀, b'(r₀)<1 and b(r)/r→0 at infinity.
- The analysis depends on a fixed but unspecified form of f(R, ℒ_m); the signs of the NEC combinations (ρ + p_r and ρ + p_t) are outputs of this choice together with the ES model, and no variation of the functional form is performed to test whether the reported ℰ ranges are structural or model-dependent.
- The second case with a particular (fixed) shape function is mentioned but no explicit comparison is given showing whether the 0.1–0.6 interval for tangential NEC persists or changes, leaving the generality of the central claim untested.
Simulated Author's Rebuttal
We thank the referee for the careful reading and constructive comments. We address each major comment point by point below, indicating where revisions will be made to improve clarity and address concerns about specificity and generality.
read point-by-point responses
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Referee: [Abstract] Abstract: the headline result that tangential NEC holds only for 0.1 ≤ ℰ ≤ 0.6 (with violations at higher values indicating throat structure) is obtained by direct substitution of the Exponential Spheroid shape function and the two chosen ℰ² forms into the modified field equations; the paper provides no demonstration that this specific interval survives for other shape functions obeying the flaring-out conditions b(r₀)=r₀, b'(r₀)<1 and b(r)/r→0 at infinity.
Authors: We agree that the reported range for tangential NEC is obtained specifically within the Exponential Spheroid model (first case, with two charge functions) and the particular shape function (second case). The manuscript does not claim or demonstrate that this interval holds for arbitrary shape functions satisfying the flaring-out conditions. We will revise the abstract to explicitly state that the findings apply to the models considered and add a clarifying remark in the discussion section on the model-specific nature of the results, noting that broader exploration of other shape functions is left for future work. revision: yes
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Referee: The analysis depends on a fixed but unspecified form of f(R, ℒ_m); the signs of the NEC combinations (ρ + p_r and ρ + p_t) are outputs of this choice together with the ES model, and no variation of the functional form is performed to test whether the reported ℰ ranges are structural or model-dependent.
Authors: The specific functional form of f(R, ℒ_m) employed is defined in the manuscript; we will make this explicit and prominent in the revised version to avoid any ambiguity. Our analysis is performed within this fixed choice of the theory to obtain the energy conditions and compare with compact objects. We concur that no variation over alternative functional forms was conducted, as that would constitute a separate study. We will add a brief note in the conclusions acknowledging this model dependence and the potential for future investigations into other forms. revision: partial
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Referee: The second case with a particular (fixed) shape function is mentioned but no explicit comparison is given showing whether the 0.1–0.6 interval for tangential NEC persists or changes, leaving the generality of the central claim untested.
Authors: The second case is presented to study the implications of an alternative shape function on the energy density and pressure profiles. While the expressions are derived, we did not provide a direct numerical comparison of the tangential NEC range. We will revise the manuscript to include an explicit comparison between the two cases, indicating whether and how the 0.1–0.6 interval changes or persists under the particular shape function. revision: yes
Circularity Check
No circularity: explicit model-dependent NEC evaluation
full rationale
The paper substitutes chosen Exponential Spheroid shape functions and two explicit E^2(r) forms into the modified field equations, then computes the resulting ρ, p_r, p_t and checks the sign of the NEC combinations for different numerical values of the charge parameter E. The quoted interval 0.1 ≤ E ≤ 0.6 is the direct numerical output of that substitution for the adopted ansätze; it is not obtained by fitting E to a subset of data and then relabeling the fit as a prediction, nor does any step reduce to a self-citation or self-definition. The second case (fixed shape function) is likewise an explicit calculation. Because the derivation chain consists of algebraic substitution followed by inequality checks on the output expressions, the reported ranges are model-specific results rather than tautological restatements of the inputs. No load-bearing uniqueness theorem or ansatz smuggling is invoked.
Axiom & Free-Parameter Ledger
free parameters (1)
- charge parameter E
axioms (2)
- domain assumption The wormhole metric is static and spherically symmetric with the given shape function and charge function forms.
- domain assumption The modified gravity function f(R, L_m) admits the standard field equations used to obtain the stress-energy components.
Reference graph
Works this paper leans on
-
[1]
Flamm, Contributions to Einstein’s theory of gravitation, Hirzel, 1916
L. Flamm, Contributions to Einstein’s theory of gravitation, Hirzel, 1916
work page 1916
-
[2]
A. Einstein, N. Rosen, The Particle Problem in the General Theory of Relativity, Phys. Rev. 48 (1935) 73–77. doi:10.1103/PhysRev.48.73
-
[3]
J. A. Wheeler, Geons, Phys. Rev. 97 (1955) 511–536. doi:10.1103/ PhysRev.97.511. 24
work page 1955
-
[4]
C. W. Misner, J. A. Wheeler, Classical physics as geometry, Annals of Physics 2 (6) (1957) 525–603. doi:https://doi.org/10.1016/ 0003-4916(57)90049-0
work page 1957
-
[5]
M. S. Morris, K. S. Thorne, Wormholes in spacetime and their use for interstellar travel: A tool for teaching general relativity, American Jour- nal of Physics 56 (5) (1988) 395–412. doi:https://doi.org/10.1119/ 1.15620
work page 1988
-
[6]
M. Visser, Lorentzian Wormholes. From Einstein to Hawking, Woodbury (1995)
work page 1995
-
[7]
K. A. Bronnikov, A. M. Galiakhmetov, Wormholes without exotic mat- ter in Einstein–Cartan theory, Gravitation and Cosmology 21 (2015) 283–288. doi:https://doi.org/10.1134/S0202289315040027
-
[8]
Soni, Sagar V. and Khunt, A. C. and Hasmani, A. H., A study of Morris- Thorne wormhole in Einstein-Cartan theory, International Journal of Geometric Methods in Modern Physics 21 (06) (2024) 2450115. doi: 10.1142/S0219887824501159
-
[9]
A. Banerjee, A. Pradhan, T. Tangphati, F. Rahaman, Wormhole geome- tries in f(Q) gravity and the energy conditions, The European Physical Journal C 81 (2021) 1031. doi:10.1140/epjc/s10052-021-09854-7
-
[10]
F. Parsaei, S. Rastgoo, P. K. Sahoo, Wormhole in f(Q) gravity, The European Physical Journal Plus 137 (2022) 1083. doi:10.1140/epjp/ s13360-022-03298-y
-
[11]
S. Chaudhary, S. Maurya, J. Kumar, S. Ray, Stability analysis of worm- hole solutions in f(Q) gravity utilizing Karmarkar condition with radial dependent redshift function, Astroparticle Physics 162 (2024) 103002. doi:https://doi.org/10.1016/j.astropartphys.2024.103002
-
[12]
M. Jan, A. Ashraf, A. Basit, A. Caliskan, E. G¨ udekli, Traversable Worm- hole in f(Q) Gravity Using Conformal Symmetry, Symmetry 15 (4) (2023). doi:10.3390/sym15040859
-
[13]
F. S. N. Lobo, M. A. Oliveira, Wormhole geometries in f(R) modified theories of gravity, Physical Review D 80 (10) (2009) 104012. doi: 10.1103/PhysRevD.80.104012. 25
-
[14]
K. A. Bronnikov, A. A. Starobinsky, No static spherically symmetric wormholes in scalar-tensor andf(R) gravity, JETP Letters 85 (1) (2007) 1–5. doi:10.1134/S0021364007010018
-
[15]
P. Pavlovic, M. Sossich, Wormholes in viable f(R) modified theories of gravity and Weak Energy Condition, European Physical Journal C 75 (3) (2015) 117. doi:10.1140/epjc/s10052-015-3347-3
-
[16]
S. H. Mazharimousavi, M. Halilsoy, Wormhole solutions in f(R) gravity satisfying energy conditions, Modern Physics Letters A 31 (16) (2016) 1650093. doi:10.1142/S0217732316500938
-
[17]
S. Bahamonde, U. Camci, Exact traversable wormhole solutions in f(R) gravity by Noether symmetry approach, Symmetry 10 (12) (2018) 774. doi:10.3390/sym10120774
-
[18]
P. H. R. S. Moraes, P. K. Sahoo, Modeling wormholes inf(R, T) gravity, Physical Review D 96 (4) (2017) 044038. doi:10.1103/PhysRevD.96. 044038
-
[19]
N. Godani, G. C. Samanta, Traversable wormholes and energy con- ditions with two different shape functions in f(R) gravity, Interna- tional Journal of Modern Physics D 28 (2) (2019) 1950039. doi: 10.1142/S0218271819500398
-
[20]
S. Capozziello, A. S. Ditta, E. N. Saridakis, K. Yin, Traversable Worm- holes with Vanishing Sound Speed in f(R) Gravity, European Physical Journal C 81 (2) (2021) 134. doi:10.1140/epjc/s10052-021-08996-y
-
[21]
O. Bertolami, C. G. B¨ ohmer, T. Harko, F. S. N. Lobo, Extra force in f(R) modified theories of gravity, Phys. Rev. D 75 (2007) 104016. doi:10.1103/PhysRevD.75.104016
-
[23]
L. V. Jaybhaye, S. Bhattacharjee, P. Sahoo, Baryogenesis in f(R, Lm) gravity, Physics of the Dark Universe 40 (2023) 101223. doi:https: //doi.org/10.1016/j.dark.2023.101223. 26
-
[24]
N. Kavya, V. Venkatesha, G. Mustafa, P. Sahoo, S. Divya Rashmi, Static traversable wormhole solutions in f(R, Lm) gravity, Chinese Journal of Physics 84 (2023) 1–11. doi:https://doi.org/10.1016/j.cjph. 2023.05.002
-
[26]
T. Naseer, M. Sharif, A. Fatima, S. Manzoor, Constructing traversable wormhole solutions in f(R, Lm) theory, Chinese Journal of Physics 86 (2023) 350–360. doi:https://doi.org/10.1016/j.cjph.2023.10. 032
-
[27]
L. V. Jaybhaye, M. Tayde, P. K. Sahoo, Wormhole solutions under the effect of dark matter in f(R, Lm) gravity, Communications in Theoreti- cal Physics 76 (5) (2024) 055402. doi:10.1088/1572-9494/ad3746
-
[28]
J. Pawde, R. Mapari, V. Patil, et al., Anisotropic behavior of universe in f(R, Lm) gravity with varying deceleration parameter, European Physi- cal Journal C 84 (2024) 320. doi:10.1140/epjc/s10052-024-12646-4
-
[30]
S.-W. Kim, H. Lee, Exact solutions of a charged wormhole, Phys. Rev. D 63 (2001) 064014. doi:10.1103/PhysRevD.63.064014
-
[31]
E. F. Eiroa, G. E. Romero, Linearized Stability of Charged Thin-Shell Wormholes, General Relativity and Gravitation 36 (2004) 651–659.doi: 10.1023/B:GERG.0000016916.79221.24
-
[32]
J. A. Gonz´ alez, F. S. Guzm´ an, O. Sarbach, Instability of charged worm- holes supported by a ghost scalar field, Phys. Rev. D 80 (2009) 024023. doi:10.1103/PhysRevD.80.024023
-
[33]
K. Bronnikov, S. Grinek, Conformal continuations and wormhole insta- bility in scalar-tensor gravity, Gravitation & Cosmology 10 (2004). 27
work page 2004
-
[34]
J. A. Gonz´ alez, F. S. Guzm´ an, O. Sarbach, Instability of wormholes supported by a ghost scalar field: I. Linear stability analysis, Classical and Quantum Gravity 26 (1) (2008) 015010. doi:10.1088/0264-9381/ 26/1/015010
-
[35]
M. Sharif, S. Rani, Charged Noncommutative Wormhole Solutions in f(T ) Gravity, European Physical Journal Plus 129 (2014) 237. doi: 10.1140/epjp/i2014-14237-5
-
[36]
P. H. R. S. Moraes, W. de Paula, R. A. C. Correa, Charged wormholes in f(R, T)-extended theory of gravity, International Journal of Modern Physics D 28 (08) (2019) 1950098. doi:10.1142/S0218271819500986
-
[37]
T. Harko, Modified gravity with arbitrary coupling between matter and geometry, Physics Letters B 669 (5) (2008) 376–379. doi:https://doi. org/10.1016/j.physletb.2008.10.007
- [38]
- [39]
-
[40]
N. M. Garcia, F. S. N. Lobo, Wormhole geometries supported by a nonminimal curvature-matter coupling, Phys. Rev. D 82 (2010) 104018. doi:10.1103/PhysRevD.82.104018
-
[41]
T. Harko, F. S. N. Lobo, J. P. Mimoso, D. Pav´ on, Gravitational induced particle production through a nonminimal curvature–matter coupling, Eur. Phys. J. C 75 (2015) 386. doi:10.1140/epjc/ s10052-015-3620-5
-
[42]
Y. Sofue, Rotation curve and mass distribution in the galactic cen- ter—from black hole to entire galaxy—, Publications of the Astronomi- cal Society of Japan 65 (6) (2013) 118
work page 2013
-
[43]
S. M. Carroll, Spacetime and Geometry: An Introduction to Gen- eral Relativity, Cambridge University Press, 2019. doi:10.1017/ 9781108770385. 28
work page 2019
-
[44]
A. Khunt, V. Thomas, P. Vinodkumar, Distinct classes of compact stars based on geometrically deduced equations of state, International Journal of Modern Physics D 30 (04) (2021) 2150029. doi:https://doi.org/ 10.1142/S0218271821500292
- [45]
-
[46]
F. Douchin, P. Haensel, A unified equation of state of dense matter and neutron star structure, Astronomy & Astrophysics 380 (1) (2001) 151–167. doi:https://doi.org/10.1051/0004-6361:20011402
-
[47]
Strange stars - linear approximation of the EOS and maximum QPO frequency
J. Zdunik, Strange stars-linear approximation of the EOS and maximum QPO frequency, arXiv preprint astro-ph/0004375 (2000)
work page internal anchor Pith review Pith/arXiv arXiv 2000
-
[48]
R. Solanki, Z. Hassan, P. Sahoo, Wormhole solutions in f(R, Lm) grav- ity, Chinese Journal of Physics 85 (2023) 74–88. doi:https://doi. org/10.1016/j.cjph.2023.06.005
-
[49]
M. S. Morris, K. S. Thorne, U. Yurtsever, Wormholes, time machines, and the weak energy condition, Physical Review Letters 61 (13) (1988)
work page 1988
-
[50]
doi:https://doi.org/10.1103/PhysRevLett.61.1446
-
[51]
J. Wang, K. Liao, Energy conditions in f(R, Lm) gravity, Classical and Quantum Gravity 29 (21) (2012) 215016. doi:10.1088/0264-9381/29/ 21/215016. 29
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