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REVIEW 3 major objections 6 minor 44 references

Extended Phase Space Thermodynamics and Joule-Thomson Expansion of Regular AdS Black Holes in a String Cloud

T0 review · 3 major / 6 minor · reviewed 2026-07-30 · grok-4.5

Pith's one-line read A regularizing core only rescales critical points of a string-cloud AdS black hole, while the string density itself changes the Van der Waals compressibility ratio; critical exponents stay mean-field.

desk verdict Solid incremental cataloguing of P–V and JT for a new regular+string-cloud AdS metric, undercut by a real entropy/first-law inconsistency. read the letter →

arxiv 2607.26931 v1 pith:AOCJ7UKG submitted 2026-07-29 hep-th

classification hep-th
keywords RegularBlackHoleStringCloudBackgroundExtendedPhaseSpaceThermodynamicsP-VCriticalityJoule-ThomsonExpansionCriticalexponentsAdSholes
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 builds the extended-phase-space thermodynamics of a static regular Anti-de Sitter black hole sitting in a cloud of strings. Treating the cosmological constant as pressure, it shows that the length scale that smooths out the central singularity only sets the overall size of the critical point: critical radius, temperature and pressure scale with that length, so their compressibility ratio stays fixed. The dimensionless string-cloud density, by contrast, really changes the equation of state and pushes that same ratio away from the classical value. The critical exponents nevertheless remain those of ordinary mean-field Van der Waals theory, and the Joule–Thomson inversion curves cleanly separate isenthalpic cooling from heating. The result gives a complete thermodynamic map of a non-singular spacetime whose geometry is deformed by both a quantum-inspired core and a macroscopic string background.

What carries the argument

An effective specific volume v = 2r+(1 − r+Ψ′/3Ψ) that absorbs the regularizing factor Ψ, turning the equation of state into a compact Van der Waals form whose inflection points yield the critical data and the scale-invariant ratio ρc = Pc(2rc)/Tc.

What would settle it

Derive the entropy by integrating the first law consistently with the mass function, recompute the critical points and ρc; if the new ρc is no longer constant under changes of r0, or the exponents leave the mean-field class, the central claim fails.

Watch

Extended reading notes

Core claim

For this regular string-cloud AdS black hole the critical compressibility ratio is strictly invariant under changes of the regularizing scale r0, while the dimensionless string-cloud parameter systematically shifts the ratio; the critical exponents remain the mean-field values α=0, β=1/2, γ=1, δ=3, and the Joule–Thomson inversion curves mark the boundary between isenthalpic cooling and heating.

Load-bearing premise

Entropy is taken to be exactly one-quarter of the horizon area even though the paper itself says regular black holes deviate from that area law and that entropy should also depend on the core scale.

Editorial extensions

If this is right

  • The regularizing core leaves a finite remnant thermodynamic volume as the horizon shrinks to zero, forbidding a point singularity.
  • Increasing string-cloud density lowers critical temperature and pressure and enlarges the cooling region under isenthalpic expansion.
  • Gibbs free-energy swallowtails and heat-capacity divergences still mark a first-order small/large black-hole transition that ends at a mean-field critical point.
  • The same thermodynamic map can be applied directly to the rotating counterpart of the metric once spin is included.

Reading between the lines

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

  • If the area-law entropy is replaced by a consistent Wald or first-law entropy that depends on r0, the reported scale invariance of ρc may become only approximate, offering a sharp internal consistency test.
  • The fact that a dimensionless background density moves ρc while a dimensionful core does not suggests a general rule: only dimensionless couplings can change the universality-class numbers of black-hole fluids.
  • Holographic entanglement entropy across the same family of geometries would test whether the mean-field exponents survive on the dual CFT side.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 6 minor

Summary. The manuscript constructs a static regular AdS black hole in a Letelier string-cloud background via a prescribed effective density with exponential core factor, then studies its extended-phase-space thermodynamics. Identifying P = −Λ/8π, the authors derive mass, Hawking temperature, thermodynamic volume, an equation of state, P–v criticality, Gibbs free energy, heat capacity, and Joule–Thomson inversion curves. The central claims are that the regularizing scale r0 leaves the critical compressibility ratio ρc = Pc(2rc)/Tc invariant (scale invariance), while the dimensionless string density ε systematically shifts ρc away from the classical 3/8 value; critical exponents remain mean-field; and JT isenthalps divide cooling and heating regimes.

Significance. If the thermodynamic bookkeeping is consistent, the paper supplies a clear, concrete addition to the regular-AdS and string-cloud thermodynamics literature: an explicit metric with both a quantum-inspired core and a string cloud, numerical critical tables that separate the roles of a dimensionful regulator (r0) from a dimensionless background (ε), and a full JT map. The reported r0-invariance of ρc at fixed ε is a sharp, falsifiable structural statement grounded in dimensional analysis and supported by Table 3. The work is incremental rather than conceptual, but the parameter decoupling and the JT section are useful reference results for this geometry.

major comments (3)
  1. [§3.2–3.3] §3.2–3.3, Eqs. (23)–(29): The entropy treatment is internally contradictory and load-bearing. The text first asserts that “for regular black holes, the entropy deviates from the Bekenstein–Hawking area law,” then immediately imposes S = πr+² (Eq. 23) with no core correction. Two paragraphs later it states that “the entropy S relies solely on r+ and r0 (see Eq. (23)),” yet Eq. (23) has no r0 dependence. The extended first law (27) and Smarr relation (29) are written as if this S is conjugate to the surface-gravity temperature (22). Because CP, the Clapeyron slope ΔS/ΔV, Maxwell construction, and μJT all inherit S, the authors must either (i) justify S = A/4 from the Einstein–Hilbert + matter action (Wald) and delete the “deviates” / “depends on r0” claims, or (ii) compute S by integrating (∂M/∂r+)/T at fixed P,ε,r0 and recompute the critical and stability results if the integral differs f
  2. [§4, Tables 2–3] §4, Eqs. (30)–(32) vs. Tables 2–3: The equation of state is rewritten with an effective specific volume v = 2r+(1 − r+Ψ′/(3Ψ)), but the compressibility ratio that underwrites the headline claim is defined with the proxy ρc = Pc(2rc)/Tc. For r0 > 0 the factor (1 − r+Ψ′/(3Ψ)) is not unity at criticality, so the tabulated ρc ≈ 0.479 is not the ratio formed from the same v that appears in the VdW-like EOS. Please recompute ρc using vc from Eq. (31) (or clearly redefine the reported ratio and explain why the proxy is preferred). The qualitative statement that ε shifts the ratio while r0 does not may survive, but the quantitative values and the comparison to 3/8 need to be consistent with the EOS variable actually used.
  3. [§4.2] §4.2: The critical-exponent analysis expands the reduced EOS to p ≈ At − Btω − Cω³ and then reads off mean-field values (α=0, β=1/2, γ=1, δ=3). That expansion forces the exponents by construction for any analytic EOS with a cubic inflection; it does not by itself demonstrate that “geometric inconsistencies result in” mean-field exponents (abstract). Please reframe: state that the EOS remains in the mean-field universality class despite the modified ρc, and note that α=0 follows from Cv=0 once S=S(r+) only. No new computation is required, but the causal wording overclaims what the Taylor argument shows.
minor comments (6)
  1. [Abstract] Abstract: “The significant geometric inconsistencies result in computed critical exponents…” is unclear and reads as a negative assessment of the model. Rephrase to the intended meaning (e.g., that geometric modifications do not change the universality class).
  2. [§3.2] §3.2, sentence introducing entropy is grammatically broken (“area law [12,21]. which states”). Fix and align the citation claim with the formula actually used.
  3. [Table 2] Table 2 caption repeats “the critical radius r0” where rc is meant; several figure captions use “Regular -AdS” with an extra space/hyphen.
  4. [§2] §2: The local NEC violation for ε>0 is noted; a one-sentence remark on whether this affects thermodynamic stability interpretations (beyond the usual regular-core caveat) would help non-specialist readers.
  5. [§4.1] Limiting cases and recovery of Schwarzschild-AdS / Letelier-AdS are useful; consider adding the ε=0, r0→0 analytic critical ratio as a sanity check against Kubizňák–Mann in the text near Tables 2–3.
  6. [References] References: preprint [44] is cited as “Preprint/Accepted”; update status if possible. A few related regular + string-cloud thermodynamics works already in the list could be contrasted more explicitly in the introduction for novelty placement.

Circularity Check

1 steps flagged · score 2.0 of 10

Mostly non-circular application of standard extended-phase-space thermodynamics; the only by-construction step is the mean-field critical-exponent claim forced by the cubic reduced EOS expansion.

  1. self definitional [§4.2 Critical Exponents, Eqs. (33)–(34) and following bullet list; cf. Abstract]
    "By substituting these reduced variables into our equation of state and performing a Taylor series expansion near the critical point (t≈0, ω≈0), the reduced pressure takes the standard form: p≈At−Btω−Cω³+O(tω²,ω⁴)... As a consequence, the critical exponents take the mean-field value: ... α=0 ... β=1/2 ... γ=1 ... δ=3. Remarkably, these derived critical exponents ... perfectly match the standard values of classical mean-field theory. This proves that while the string cloud background and the regularizing core significantly alter the critical values ... they do not change the fundamental universa"

    The ‘derivation’ assumes the generic analytic cubic expansion of any van der Waals-like EOS about an inflection point. From p≈At−Btω−Cω³ the four mean-field exponents follow by definition (Cv=0⇒α=0; Maxwell on the odd cubic⇒β=1/2; ∂p/∂ω∼−Bt⇒γ=1; t=0⇒p∼−Cω³⇒δ=3). No property special to r0 or ε enters the exponent algebra. Framing this as a geometric result that ‘aligns with’ or is ‘proved’ by the model is self-definitional: the output is the input template. The Abstract’s phrase that geometric inconsistencies ‘result in’ mean-field exponents overstates the same tautology. This affects only the exponent claim, not ρc tables or JT curves.

full rationale

The paper builds a regular AdS+string-cloud metric from a prescribed effective density, then applies the usual Kubizňák–Mann extended-phase-space pipeline (M as enthalpy, P=−Λ/8π, EOS, Maxwell construction, Gibbs swallowtail, CP, JT inversion). Critical coordinates and the ε-dependence of ρc are obtained by solving inflection conditions on that EOS; the r0-invariance of ρc is a dimensional consequence (rc∝r0, Tc∝1/r0, Pc∝1/r0²) checked numerically in Table 3—not a fit renamed as a prediction. Self-citation [44] only points to the authors’ rotating counterpart for shadow/evaporation context and is not load-bearing for the thermodynamic claims. The sole mild circularity is §4.2: once the reduced EOS is written p≈At−Btω−Cω³, the exponents (α,β,γ,δ)=(0,1/2,1,3) are forced by that Landau/mean-field template, so the claim that the geometry ‘results in’ mean-field exponents overstates independence. That does not make the central ρc/JT results tautological. Entropy bookkeeping inconsistencies noted elsewhere are correctness risks, not circular reductions.

Assumptions & free parameters 3 free parameters · 6 assumptions · 2 invented entities

The paper sits entirely inside classical GR plus phenomenological matter: Einstein equations with Λ, a Letelier string cloud, and an invented effective density that enforces a regular core. Extended-phase-space dictionary (P=−Λ/8π, M=enthalpy) and area-law entropy are imported. Free parameters r0 and ε are model knobs scanned numerically; no empirical fit to observation. Invented content is the particular ρeff profile and the resulting metric, not a new fundamental field with external handles.

free parameters (3)
  • r0 (regularizing length) = scanned values e.g. 0.4–1.2; often 0.5
    Phenomenological core scale chosen by hand in all plots/tables; sets absolute critical scales. Not fixed by a microscopic theory in the paper.
  • ε (string cloud density) = scanned 0, 0.3, 0.6, 0.9
    Dimensionless background parameter 0≤ε<1 chosen by hand; drives shifts in ρc and inversion curves.
  • Representative M, P for horizons/figures = M=1.0, P=0.01 (horizons); various sub/super-critical P/T
    Illustration choices (e.g. M=1, P=0.01; masses 0.3–0.5 for JT) fix figure appearance but not the qualitative claims.
assumptions (6)
  • domain assumption Negative cosmological constant is thermodynamic pressure P=−Λ/8π and black-hole mass is enthalpy in the extended first law.
    Standard extended phase space framework cited from Kastor/Dolan/Kubizňák–Mann; assumed from §1 and §3 onward.
  • ad hoc to paper Entropy equals horizon area/4, S=πr+², with no additional regular-core correction.
    Stated in Eq. (23) despite surrounding text claiming regular BHs deviate from area law; used for G, CP, Clapeyron, and JT.
  • ad hoc to paper Effective matter is an anisotropic fluid with pr=−ρeff and the prescribed density ρeff(r) involving exp(−r³/r0³) plus string terms (Eq. 7).
    Phenomenological input that defines the whole geometry; not derived from a fundamental action beyond naming I_eff.
  • domain assumption Classical Letelier string-cloud stress tensor T^t_t=T^r_r=−ε/(8πr²), angular pressures zero.
    Taken from Letelier 1979 and used in Eqs. (4)–(11).
  • standard math Critical exponents are read from a local cubic Landau/mean-field expansion of the reduced equation of state.
    Standard classification method in AdS black-hole thermodynamics literature; §4.2.
  • standard math Natural units G=ℏ=c=kB=lp=1; static spherical symmetry with g_tt=−1/g_rr.
    Stated at end of §1 and metric ansatz (5).
invented entities (2)
  • Specific regularizing effective density ρeff(r) (Eq. 7) and resulting mass function M(r)=(M+εr/2)(1−e^{−r³/r0³})
    purpose: Produce a non-singular core while recovering Letelier–AdS at infinity and enabling thermodynamic analysis.
    Profile is prescribed to enforce regularity and match desired asymptotics; curvature invariants are checked finite, but the matter model is phenomenological.
  • Effective specific volume v=2r+(1−r+Ψ′/(3Ψ)) used to cast P in VdW-like form
    purpose: Rewrite the equation of state in a compact Van der Waals-like structure.
    Definition chosen to absorb a modulating factor in Eq. (30); not the geometric 2r+ used later as proxy for ρc.

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Cite this review

Pith. "Pith review of Extended Phase Space Thermodynamics and Joule-Thomson Expansion of Regular AdS Black Holes in a String Cloud." pith.science (2026). https://pith.science/paper/AOCJ7UKG

@misc{pith2026260726931,
  author       = {Pith},
  title        = {Pith review of: Extended Phase Space Thermodynamics and Joule-Thomson Expansion of Regular AdS Black Holes in a String Cloud},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/AOCJ7UKG}},
  note         = {Machine review of arXiv:2607.26931}
}
read the original abstract

We investigate the extended phase space thermodynamics of a static, spherically symmetric regular black hole immersed in a string cloud background. By identifying the negative cosmological constant as a thermodynamic pressure, our analysis indicates that the quantum-inspired regularizing core and the string cloud density significantly affect the thermal stability of the black hole. We specifically illustrate a stringent scale invariance linked to the regularizing core, while the dimensionless string cloud parameter substantially alters the universal Van der Waals critical compressibility ratio. The significant geometric inconsistencies result in computed critical exponents that align with those of mean-field theory. We specify the Joule-Thomson expansion to define the isenthalpic heating and cooling regimes, so providing a comprehensive thermodynamic characterization of this non-singular spacetime.

Figures

Figures reproduced from arXiv: 2607.26931 by the authors.

Figure 1
Figure 1. Behavior of the metric function f(r) with respect to the radial coordinate r for M = 1.0 and P = 0.01. The intersections with the f(r) = 0 axis denote the locations of the horizons r− and r+. study on the rotating counterpart of this solution, where the string cloud parameter was likewise shown to enlarge the event horizon and modify the spacetime geometry [44]. The geometric deformation of the event horizon is furt… view at source ↗
Figure 2
Figure 2. 3D spatial embeddings of the outer event horizon surface [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. Hawking temperature T as a function of r+ for ϵ = 0.3 and r0 = 0.5. The Hawking temperature is depicted in [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figures from the paper (9 more)
Figure 4
Figure 4. Figure 4: The P − v isotherms for the regular black hole with fixed r0 = 0.5 and varying string cloud densities ϵ. 4.1 Critical Behavior and Scale Invariance To quantify the impact of the parameters on the phase transitions, we numerically solve for the critical points, satisfyi…
Figure 5
Figure 5. Figure 5: The P − v isotherms for a fixed string cloud ϵ = 0.3 and varying regularizing core r0. ϵ r0 rc Tc Pc ρc = Pc(2rc) Tc 0.3 0.4 0.853199 0.125045 0.0351360 0.479191 0.3 0.6 1.279800 0.0833635 0.0156160 0.479191 0.3 0.9 1.919700 0.0555757 0.0069404 0.479191 0.3 1.2 2.55960…
Figure 6
Figure 6. Figure 6: Gibbs free energy G vs T for varying ϵ. This topological feature corresponds to the unstable oscillating region in the P − v diagrams and confirms the transition from the SBH state to the LBH state at the crossing point where the free energies of the two phases are equ…
Figure 7
Figure 7. Figure 7: Gibbs free energy G vs T for fixed ϵ = 0.3 and varying r0. Coexistence phase 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.000 0.005 0.010 0.015 0.020 0.025 T P P-T Coexistence Curve for Regular-AdS BH (ϵ=0.3, r0=0.5) Critical Point [PITH_FULL_IMAGE:figures/full_fig_p015_7.png]
Figure 8
Figure 8. Figure 8: The P −T coexistence curve for the regular AdS black hole with string cloud (ϵ = 0.3, r0 = 0.5). The curve separates the SBH phase (upper left) from the LBH phase (lower right) and terminates strictly at the critical point (Tc, Pc). 15 [PITH_FULL_IMAGE:figures/full_fi…
Figure 9
Figure 9. Figure 9: Heat capacity CP versus r+ for varying string cloud parameter ϵ at fixed r0 = 0.5. The system exhibits classic van der Waals-like thermodynamic behavior across all tested parameters. For sub-critical pressures (P = 0.4Pc), CP suffers from two infinite discontinuities t…
Figure 10
Figure 10. Figure 10: Isobaric heat capacity CP versus r+ for fixed ϵ = 0.3 and varying regularizing scale r0. Similarly, the structural properties of the phase transition are highly sensitive to the reg￾ularization parameter r0 ( [PITH_FULL_IMAGE:figures/full_fig_p017_10.png]
Figure 11
Figure 11. Figure 11: Joule-Thomson expansion (T −P diagram) for the regular AdS black hole with string cloud (ϵ = 0.3, r0 = 0.5). The solid curves represent isenthalpic processes for constant mass M. The dashed line represents the inversion curve connecting the maxima of the isenthalpics,…
Figure 12
Figure 12. Figure 12: The inversion curves for the Joule-Thomson expansion. Panel (a) illustrates the [PITH_FULL_IMAGE:figures/full_fig_p019_12.png]

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Works this paper leans on

44 extracted references · 2 linked inside Pith

  1. [1]

    J. D. Bekenstein,Black holes and entropy, Phys. Rev. D7, 2333 (1973)

  2. [2]

    S. W. Hawking,Particle creation by black holes, Commun. Math. Phys.43, 199 (1975)

  3. [3]

    Chamblin, R

    A. Chamblin, R. Emparan, C. V. Johnson, and R. C. Myers,Holography, thermodynamics, and fluctuations of charged AdS black holes, Phys. Rev. D60, 104026 (1999)

  4. [4]

    Kastor, S

    D. Kastor, S. Ray, and J. Traschen,Enthalpy and the mechanics of AdS black holes, Class. Quantum Grav.26, 195011 (2009)

  5. [5]

    O. B. Zaslavskii,Regular black holes and energy conditions,Phys. Lett. B688, 278-280 (2010). [arXiv:1004.2362 [gr-qc]]

  6. [6]

    B. P. Dolan,The cosmological constant and the black hole equation of state, Class. Quantum Grav.28, 235017 (2011)

  7. [7]

    Cvetič, G

    M. Cvetič, G. W. Gibbons, D. Kubizňák, and C. N. Pope,Black hole enthalpy and an entropy inequality for the thermodynamic volume, Phys. Rev. D84, 024037 (2011)

  8. [8]

    Kubizňák and R

    D. Kubizňák and R. B. Mann,P-V criticality of charged AdS black holes, JHEP2012, 33 (2012)

Show all 44 references
  1. [9]

    Wei and Y.-X

    S.-W. Wei and Y.-X. Liu,Insight into the Microscopic Structure of an AdS Black Hole from a Thermodynamical Phase Transition, Phys. Rev. Lett.115, 111302 (2015)

  2. [10]

    Gunasekaran, R

    S. Gunasekaran, R. B. Mann, and D. Kubizňák,Extended phase space thermodynamics for charged and rotating black holes and Born-Infeld vacuum polarization, JHEP2012, 110 (2012). 20

  3. [11]

    Altamirano, D

    N. Altamirano, D. Kubizňák, R. B. Mann, and Z. Sherkatghanad,Thermodynamics of rotating black holes and black rings: phase transitions and thermodynamic volume, Galaxies 2, 89 (2014)

  4. [12]

    S. H. Hendi, R. B. Mann, S. Panahiyan, and B. Eslam Panah,Extended phase space ther- modynamics and P-V criticality of black holes with a non-linear source, Phys. Rev. D95, 021501(R) (2017)

  5. [13]

    Banerjee and D

    R. Banerjee and D. Roychowdhury,Thermodynamics of phase transition in higher dimen- sional AdS black holes, JHEP2011, 4 (2011)

  6. [14]

    B. R. Majhi and S. Samanta,Thermodynamics and phase transition of a generic higher derivative gravity black hole, Phys. Lett. B773, 203 (2017)

  7. [15]

    H. F. Li, M. S. Ma and Y. Q. Ma,Thermodynamic properties of black holes in de Sitter space,Mod. Phys. Lett. A32(2016) no.02, 1750017

  8. [16]

    Poisson and W

    E. Poisson and W. Israel,Internal structure of black holes, Phys. Rev. D41, 1796 (1990)

  9. [17]

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

  10. [18]

    S. A. Hayward,Formation and evaporation of regular black holes, Phys. Rev. Lett.96, 031103 (2006)

  11. [19]

    Ansoldi,Spherical black holes with regular center, arXiv:0802.0330 [gr-qc] (2008)

    S. Ansoldi,Spherical black holes with regular center, arXiv:0802.0330 [gr-qc] (2008)

  12. [20]

    Balart and E

    L. Balart and E. C. Vagenas,Regular black holes with a nonlinear electrodynamics source, Phys. Rev. D90, 124045 (2014)

  13. [21]

    Z. Y. Fan and X. Wang,Construction of Regular Black Holes in General Relativity, Phys. Rev. D94, 124027 (2016)

  14. [22]

    C. Lan, H. Yang, Y. Guo and Y. G. Miao,Regular Black Holes: A Short Topic Review,Int. J. Theor. Phys.62(2023) no.9, 202

  15. [23]

    D. V. Singh, S. G. Ghosh and S. D. Maharaj,Exact nonsingular black holes and thermody- namics,Nucl. Phys. B981(2022), 115854

  16. [24]

    M. S. Ma and R. Zhao,Corrected form of the first law of thermodynamics for regular black holes,Class. Quant. Grav.31(2014), 245014

  17. [25]

    D. V. Singh and S. Siwach,Thermodynamics and P-v criticality of Bardeen-AdS Black Hole in 4DEinstein-Gauss-Bonnet Gravity,Phys. Lett. B808(2020), 135658

  18. [26]

    Rehan, S

    M. Rehan, S. U. Islam and S. G. Ghosh,Extended phase space thermodynamics of regular- AdS black hole,Sci. Rep.14(2024) no.1, 13875

  19. [27]

    Singh, D

    B. Singh, D. Veer Singh and B. Kumar Singh,Thermodynamics, phase structure and quasi- normal modes for AdS Heyward massive black hole,Phys. Scripta99(2024) no.2, 025305

  20. [28]

    P. S. Letelier,Clouds of strings in general relativity, Phys. Rev. D20, 1294 (1979)

  21. [29]

    Ghaderi and B

    K. Ghaderi and B. Malakolkalami,Thermodynamics of Schwarzschild-like black hole with a cloud of strings, Astrophys. Space Sci.361, 161 (2016)

  22. [30]

    J. M. Toledo and V. B. Bezerra,Regular black holes with a cloud of strings, Annals of Physics423, 168349 (2020). 21

  23. [31]

    Nascimento, P

    F. Nascimento, P. H. Morais, J. Toledo, and V. Bezerra,Thermodynamics and geometry of string cloud spacetimes, Gen. Relativ. Gravit.56, 86 (2024)

  24. [32]

    Ma, H.-H

    M.-S. Ma, H.-H. Zhao, L.-C. Cao, and Z.-H. Zheng,Thermodynamic phase transition of a black hole in a string cloud background, Int. J. Mod. Phys. A31, 1650120 (2016)

  25. [33]

    L. C. N. Santos et al.,Regular black holes in a string cloud background, Gen. Relativ. Gravit. 54, 109 (2022)

  26. [34]

    C. R. Muniz, J. A. Rebouças, L. T. de Oliveira, F. T. B. Sampaio and F. B. Lustosa, Regularized black hole solution from a new string cloud source,Phys. Dark Univ.52(2026), 102272

  27. [35]

    V. K. Mishra and M. Pandey,Thermodynamic Structure of Einstein-Gauss-Bonnet Regular Black Holes Coupled with Cloud of String,JHAP6(2026) no.2, 87-103

  28. [36]

    D. V. Singh, S. Upadhyay, Y. Myrzakulov, K. Myrzakulov, B. Singh and M. Kumar,Ther- modynamic behavior and phase transitions of black holes with a cloud of strings and perfect fluid dark matter,Nucl. Phys. B1016(2025), 116915

  29. [37]

    Daassou, R

    A. Daassou, R. Benbrik and H. Laassiri,Effect of a cloud of strings and quintessence on a phase transition of charged rotating AdS black holes,Theor. Math. Phys.215(2023) 893–908

  30. [38]

    Ökcü and E

    Ö. Ökcü and E. Aydıner,Joule-Thomson expansion of the charged AdS black holes, Eur. Phys. J. C77, 24 (2017)

  31. [39]

    Mo, G.-Q

    J.-X. Mo, G.-Q. Li, S.-Q. Lan, and X.-B. Xia,Joule-Thomson expansion ofd-dimensional charged AdS black holes, Phys. Rev. D98, 124032 (2018)

  32. [40]

    K. V. Yerra and C. Bhamidipati,Joule-Thomson expansion of black holes in the extended phase space, Int. J. Mod. Phys. A33, 1850085 (2018)

  33. [41]

    Spallucci and A

    E. Spallucci and A. Smailagic,Maxwell’s equal area law for charged Anti-deSitter black holes, Phys. Lett. B723, 436 (2013)

  34. [42]

    Lekbich, A

    H. Lekbich, A. El Boukili, N. Mansour and M. B. Sedra,4D AdS Einstein–Gauss–Bonnet black hole endowed with Lorentzian noncommutativity:P−Vcriticality, Joule–Thomson expansion, and shadow,Ann. Phys.458(2023) 169451

  35. [43]

    C. Li, P. He, P. Li and J. B. Deng,Joule-Thomson expansion of the Bardeen-AdS black holes,Gen. Rel. Grav.52(2020) no.5, 50

  36. [44]

    Elaima, H

    Y. Elaima, H. Lekbich, A. Daassou, and F. Oubbad,Rotating Regular Black Hole in a String Cloud Background: Thermodynamics and Shadows, [Preprint/Accepted in General Relativity and Gravitation] (2026). 22

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