Pith. sign in

REVIEW 4 major objections 4 minor 1 cited by

Effect of Noncommutative Geometry on Accretion Disks around RGI-Schwarzschild Black Hole

T0 review · 4 major / 4 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read Combining spacetime noncommutativity with a running Newton constant, this paper predicts that quantum gravity corrections shift the inner edge of a black hole's accretion disk inward and raise its peak temperature and energy flux.

desk verdict The κ-deformed RGI metric in Eq. (3.11) is just a coordinate-rescaled RGI-Schwarzschild metric, so the claimed noncommutative enhancement of disk flux is a gauge artifact. read the letter →

arxiv 2507.13056 v2 pith:Q64YE3GF submitted 2025-07-17 gr-qc hep-ph

classification gr-qchep-ph MSC 83C5783C1081T7583C55 PACS 04.70.-s04.60.-m02.40.Gh
keywords kappa-deformedspacetimenoncommutativegeometryRG-improvedSchwarzschildblackholerunningNewtonconstantthinaccretiondiskISCOradiustemperaturequantumgravitysignatures
open problems Quantum Gravity
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

Quantum gravity is usually tested at particle scales, but this paper argues it can also show up in the glowing gas disks around black holes. It studies a Schwarzschild black hole whose geometry carries two quantum corrections at once: κ-deformed, noncommutative spacetime, which introduces a minimal length, and a renormalization-group-improved Newton constant that runs with distance. Using the standard thin-disk model built on circular geodesics in this modified metric, the paper finds that the innermost stable circular orbit moves inward from $x=6$ to about $x=5.24$, and that the peak radiated energy flux and disk temperature rise above the classical Schwarzschild values. The central claim is that these combined quantum gravity corrections enhance the disk's radiative efficiency near the hole, which would give astrophysical observations a concrete place to look for Planck-scale physics.

What carries the argument

The argument runs on the κ-deformed RGI-Schwarzschild metric, whose lapse is $\hat{f}(r)=1-(2M/r)(1-\tilde{\omega} e^{4ap_0}/r^2)$ and whose spatial components carry the factor $e^{-4ap_0}$; it is built from the scale identification $k=\xi/\hat{d}(r)$ with $\hat{d}(r)=e^{-2ap_0}d(r)$, which turns the running Newton constant into $G(r)\approx G_0(1-\tilde{\omega} G_0 e^{4ap_0}/r^2)$. Around this metric the paper derives the effective potential, the ISCO condition, and the orbital quantities $\hat{h}$, $\hat{k}$, and $\hat{\Omega}$, then feeds them into the standard thin-disk flux formula. The inward displacement of the potential minimum and the steepening of the flux and temperature profiles are what carry the conclusion.

What would settle it

Compute the ISCO and the disk flux using the exact, unexpanded running coupling $G(r)=G_0/(1+\omega G_0 e^{4ap_0}\xi^2/d(r)^2)$ with the full κ-deformed proper distance; if the inward ISCO shift or the rise in peak flux disappears or reverses sign, the reported enhancement is an artifact of the first-order expansion. Observationally, a high-resolution X-ray measurement of a thin-disk black hole that resolves the inner disk temperature could falsify the predicted hot inner edge if no such hardening is seen.

Watch

Extended reading notes

Core claim

The central claim is that the combined geometry, obtained by letting κ-deformation rescale spatial distances while a running Newton constant modifies the lapse, makes the inner accretion disk more compact and more luminous than in classical Schwarzschild spacetime. Concretely, for a small deformation parameter $ap_0=0.1$ and the running parameter at its critical value $\tilde{\omega}\simeq 0.39$, the ISCO radius drops from $x=6$ in the classical case to $x\simeq 5.24$, and the energy-flux and temperature profiles shown in Figs. 7 and 9 peak at higher values and closer to the horizon. The paper attributes this to a stronger effective gravitational pull near the hole, which makes orbiting matter fall faster and heat more intensely. In the commutative limit all disk quantities reduce to the classical Schwarzschild result, so the enhancement is presented as a genuine combined effect of noncommutativity and scale-dependent gravity.

Load-bearing premise

The load-bearing premise is that the quantum-gravity energy scale is set by the inverse of the κ-deformed proper distance and that the running Newton constant can be expanded to first order even close to the horizon, where the correction term is no longer tiny; if that expansion fails, the modified metric and every disk result built on it fail.

Editorial extensions

If this is right

  • Stable circular orbits exist closer to a κ-deformed RGI-Schwarzschild black hole than to a classical one, with the ISCO shifting from $x=6$ to about $x=5.24$ at the parameter values considered.
  • Peak energy flux and disk temperature are higher and shifted inward, implying enhanced radiative efficiency of the inner disk if the construction is correct.
  • The running parameter has a critical value $\tilde{\omega}_c=(16/27)e^{-4ap_0}$: below it the spacetime has two horizons, at it the horizons merge, and above it no horizon exists and a naked singularity appears.
  • Adding κ-deformation alone lowers the differential luminosity peak relative to the commutative RGI case, while the combined geometry still produces a hotter, more compact disk than classical Schwarzschild.
  • The κ-corrected mass accretion rate carries an extra factor $e^{-3ap_0}$, so noncommutativity changes the overall normalization of all disk fluxes.

Reading between the lines

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

  • A testable extension would be to turn the predicted flux profile into a spectral energy distribution and look for a systematic hardening or blue-shift of the thermal continuum in X-ray observations of thin-disk black hole candidates.
  • Repeating the ISCO and flux calculation with the unexpanded running coupling $G_0/(1+\omega G_0 e^{4ap_0}/r^2)$ would show whether the first-order expansion used near the horizon is responsible for the reported enhancement; if the exact calculation changes the sign of the effect, the paper's qualitative conclusion would not survive.
  • The same construction could be applied to a rotating background, but spin and quantum corrections both move the ISCO inward, so separating the two would require comparing the full flux shape rather than the edge radius alone.
  • If the horizonless regime $\tilde{\omega}>\tilde{\omega}_c$ is physical, disks around such objects would lack the usual innermost-stable-orbit cutoff and should display a qualitatively different thermal spectrum.
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 / 4 minor

Summary. The paper constructs a kappa-deformed, renormalization-group-improved (RGI) Schwarzschild metric by combining a kappa-deformation induced spatial rescaling e^{-4ap0} with a running Newton constant. It then derives geodesic equations, effective potential, ISCO radius, specific energy/angular momentum, and angular velocity, and applies the Page-Thorne thin-disk model to compute energy flux, differential luminosity, and temperature profiles. The central claim is that, for small deformation parameter ap0=0.1 and running parameter tilde-omega=0.39, the combined noncommutative and RG corrections increase the peak flux and temperature relative to classical Schwarzschild, with the ISCO shifting from x=6 to x approximately 5.24.

Significance. If the claimed effect were physical, the paper would provide a concrete phenomenological signature of combined noncommutative and asymptotic-safety corrections in accretion-disk observables. The manuscript is written in the standard style of the field and the Page-Thorne machinery is applied in a mostly conventional way. However, the central conclusion does not survive scrutiny: the kappa-deformed RGI metric is isometric to the standard commutative RGI-Schwarzschild metric under a coordinate rescaling, so the deformation parameter is pure gauge. The claimed noncommutative enhancement is an artifact of this coordinate redefinition and of non-invariant prefactors introduced in the flux derivation. The paper therefore does not establish a new physical effect.

major comments (4)
  1. [Sec. 3.2, Eq. (3.11)] The kappa-deformed RGI-Schwarzschild line element is not a new geometry. With R = e^{-2ap0} r, Eq. (3.11) transforms exactly into the commutative RGI-Schwarzschild metric ds^2 = -[1 - (2 M e^{-2ap0}/R)(1 - tilde-omega/R^2)] dt^2 + [1 - (2 M e^{-2ap0}/R)(1 - tilde-omega/R^2)]^{-1} dR^2 + R^2 dOmega^2. The deformation parameter a enters only through a coordinate rescaling and a redefinition of the mass parameter M' = M e^{-2ap0}; it is pure gauge. Consequently all diffeomorphism-invariant predictions (ISCO, flux, temperature) for the kappa-deformed model coincide with those of standard RGI-Schwarzschild with mass M' and the same tilde-omega. In particular, the ISCO equation (4.33) depends only on q = tilde-omega e^{4ap0}/M^2, which is exactly the effective dimensionless running parameter of the commutative RGI metric after the rescaling. The comparisons in Figs. 7-9 between 'RGI' (tilde-omega=16/27, ap0=0) and 'kappa-deformed RGI' (tilde-omega=0.39, ap0=0.1) therefore compare two commutative RGI models with nearly equal q (0.593 versus 0.582); the small plotted differences come from the slightly different q and from non-invariant prefactors in Eqs. (5.8)-(5.14), not from noncommutativity. This invalidates the central claim in the abstract that noncommutative geometry enhances the disk's radiative efficiency.
  2. [Sec. 4.3, Eq. (4.16)] The Lagrangian displayed in Eq. (4.16) is inconsistent with the metric (3.11): the radial term should have g_rr = e^{-4ap0} / f(r), but Eq. (4.16) shows e^{-4ap0} f(r) dot-r squared, i.e., f rather than 1/f. The subsequent derivation leading to Eq. (4.20) uses the correct inverse, so this appears to be a typographical error in the displayed formula; nevertheless it must be corrected because Eq. (4.16) is the starting point of the entire geodesic and ISCO analysis.
  3. [Sec. 5, Eqs. (5.9)-(5.14)] The treatment of the kappa-deformed radial velocity is internally inconsistent. From the metric (3.11), sqrt(g_hat_rr) = e^{-2ap0} sqrt(g_rr), not e^{-ap0} sqrt(g_rr) as used in Eq. (5.11). The stated invariance condition therefore gives u_hat^r = e^{2ap0} u^r, not e^{ap0} u^r. Combined with sqrt(-g_hat) = e^{-4ap0} r, the mass accretion rate in Eq. (5.13) should scale as e^{-2ap0}, not e^{-3ap0}. The extra e^{ap0} factors propagate into the flux formula (5.14) and into Figs. 7-9, so the quoted flux and temperature enhancements are not reliable even within the paper's own framework.
  4. [Sec. 3.2, Eqs. (3.5)-(3.9)] The scale identification k(r) = xi/d(r) is replaced by k(r) approximately xi/r, and the running coupling is expanded to first order in tilde-omega G0 e^{4ap0}/r^2. For the parameters used in the paper (ap0=0.1, tilde-omega=0.39), the expansion parameter near the horizon is tilde-omega e^{4ap0}/r_h^2 approximately 0.15, so the weak-field expansion is applied where it is not small. The paper itself notes in Sec. 3.2 that a more precise scale-setting is needed in strong-curvature regions, but the ISCO and disk-flux results depend precisely on the near-horizon form of the metric. This limits the quantitative reliability of the predictions even before the gauge issue is taken into account.
minor comments (4)
  1. [References] Reference [45] appears to contain a typo in the author name and an incomplete bibliographic entry; it should be checked against the original source.
  2. [Figs. 7-9] The captions of Figs. 7-9 do not clearly state the units of the vertical axes; in particular, the factor shown as '1e 5' in Fig. 7 needs to be explained in the caption so that the reader can interpret the ordinate.
  3. [Sec. 4.1, Eqs. (4.4)-(4.5)] The derivation of the critical value tilde-omega_c is abbreviated: in Eq. (4.4) the product is analyzed by declaring the first two factors 'the only possibility of M=0', which is not a complete argument; a more explicit derivation of tilde-omega_c = 16/27 e^{-4ap0} would improve the presentation.
  4. [Sec. 4.3, Eq. (4.28)] The transition from tilde-omega to the dimensionless hat-omega = tilde-omega/M^2 is not stated consistently: some equations and the text later use hat-omega while Eq. (4.33) mixes hat-omega with e^{4ap0}; the notation should be made uniform.

Circularity Check

1 steps flagged · score 8.0 of 10

The κ-deformed RGI metric (3.11) is the standard RGI-Schwarzschild metric in rescaled coordinates, so the noncommutative disk enhancement is a coordinate artifact.

  1. renaming known result [Section 3.2, Eq. (3.11); conclusions drawn in Figs. 7–9 and Section 6]
    "Thus, we obtain the line element for κ-deformed RGI-Schwarzschild space-time metric in cosmological unit (G0 = c = 1) as, dˆs2 RGI = −[1 − (2M/r)(1 − ˜ωe4ap0/r2)]dt2 + e−4ap0[1 − (2M/r)(1 − ˜ωe4ap0/r2)]−1dr2 + r2e−4ap0(dθ2+sin2θdφ2). (3.11)"

    The substitution R = e^{-2ap0} r, dR = e^{-2ap0} dr reduces Eq. (3.11) exactly to the commutative RGI-Schwarzschild line element with mass μ = M e^{-2ap0}: ds² = −[1−(2μ/R)(1−ω̃/R²)]dt² + [1−(2μ/R)(1−ω̃/R²)]^{-1}dR² + R²dΩ², which is Eq. (3.11) with ap0 = 0 and M replaced by μ. Thus the deformation parameter a enters only through a coordinate redefinition of the radial variable and a rescaling of the mass parameter; it does not define a new spacetime. All quantities computed subsequently—geodesics (Section 4.2), ISCO from Eq. (4.33), angular momentum and energy (Eqs. 4.28–4.31), flux (Eq. 5.14), luminosity (Eq. 5.15), and temperature (Eq. 5.16)—are diffeomorphism invariants of this metric, so the reported ap0 dependence in Figs. 7–9 is unphysical.

full rationale

The paper's disk model is not fitted to the output quantities: the energy flux, luminosity, and temperature are derived from the metric through the standard Page–Thorne/Novikov–Thorne thin-disk formalism, and the parameters ap0 and ω̃ are selected by hand with physical justifications. In that sense the derivation is self-contained and not statistically circular. However, the central physical claim is circular in a geometric sense: the starting κ-deformed RGI-Schwarzschild metric, Eq. (3.11), is diffeomorphic to the ordinary RGI-Schwarzschild metric under the radial rescaling R = e^{-2ap0} r, with mass parameter M e^{-2ap0}. Consequently the 'noncommutative' modifications of the geodesic equations and of the disk flux, luminosity, and temperature are just the same RGI-Schwarzschild physics expressed in a different coordinate chart; the apparent enhancement of the peak flux and temperature is forced by the coordinate choice and by comparing cases with different effective values of ω̃/M² rather than by a genuinely new noncommutative geometry. This is the strongest circularity, and it undermines the abstract's conclusion that quantum gravity corrections from noncommutativity enhance the disk's radiative efficiency. The paper itself flags an additional correctness risk in Section 3.2 ('A more precise scale-setting involving d(r) would be required only in regions of strong curvature, such as near the horizon'), which further weakens the derivation near the ISCO, but that is a limitation of the RG-scale identification rather than a circular step. No self-citation chain is load-bearing here, and no prediction is fitted to data, so the circularity score is driven entirely by the coordinate-equivalence of the central metric.

Assumptions & free parameters 3 free parameters · 5 assumptions · 0 invented entities

The central results depend on two hand-chosen parameters (ap0 and tilde-omega) and on a chain of standard but non-trivial assumptions from noncommutative geometry, asymptotic safety, and thin disk theory. No new particles or fields are introduced. The approximation that the running coupling expansion is valid near the horizon is the most fragile input.

free parameters (3)
  • ap0 (dimensionless deformation parameter) = 0.1
    Chosen by hand in Section 4.1: 'Since the effects of non-commutativity are expected to be small, we obtain ap0 ≃ 0.1'. Controls the strength of kappa-deformation.
  • tilde-omega (running parameter) = 0.39 for the kappa-deformed RGI case; 16/27 for the RGI case
    Constrained by horizon existence: tilde-omega must be <= (16/27)e^{-4ap0}. The value 0.39 is near critical for ap0=0.1 and is used to ensure two horizons exist. This is a free parameter of the RG-improvement scheme.
  • p0 (background energy scale) = not specified numerically, appears only in the product ap0
    Described as 'typically of the order of the black hole mass or the Planck scale'. It is a dimensional scale that determines when kappa-deformation effects are relevant.
assumptions (5)
  • domain assumption kappa-deformed spacetime algebra [x0, xi] = i a xi and the exponential realization phi(A) = e^{-A}, psi(A) = 1
    Section 2.1. This is the standard kappa-deformation framework from the cited noncommutative geometry literature.
  • domain assumption The generalized commutation relation [x^mu, P_nu] = i g^mu_nu with the right side interpreted as the deformed metric tensor
    Section 2.2, Eq. (2.6). This prescription connects the noncommutative algebra to the metric components and is taken from prior work on kappa-deformed field theory.
  • domain assumption The RG running coupling G(k) = G0/(1 + omega G0 k^2) from the Einstein-Hilbert truncation of asymptotic safety
    Section 3.1, Eq. (3.1). This is the standard form used in RG-improved black hole models and is cited to [42] and [43].
  • domain assumption The scale-setting k(r) = xi/d(r) and the weak-field approximation d(r) ~ r, followed by a first-order expansion of G(r) near the horizon
    Section 3.2, Eqs. (3.2)-(3.9). The identification of the RG scale with the inverse proper distance is standard at large r, but near the horizon the expansion parameter is not small, which is an unstated limitation.
  • domain assumption The Page-Thorne thin disk model assumptions: geometrically thin, optically thick, steady state, circular geodesic orbits in the equatorial plane
    Section 5. The standard assumptions of the Shakura-Sunyaev/Page-Thorne model are adopted without modification.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Effect of Noncommutative Geometry on Accretion Disks around RGI-Schwarzschild Black Hole." pith.science (2026). https://pith.science/paper/Q64YE3GF

@misc{pith2026250713056,
  author       = {Pith},
  title        = {Pith review of: Effect of Noncommutative Geometry on Accretion Disks around RGI-Schwarzschild Black Hole},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/Q64YE3GF}},
  note         = {Machine review of arXiv:2507.13056}
}
abstract

In this study, we explore the combined effects of quantum gravity induced by non-commutativity and scale-dependent gravitational coupling on the thermal properties of the thin accretion disks around a Schwarzschild black hole. We consider a $\kappa$-deformed Renormalization Group Improved (RGI) Schwarzschild black hole, where the classical Schwarzschild black hole geometry is modified by the $\kappa$-deformation of space-time and the running Newton's coupling constant $G(r)$. Using the modified metric, we derive the geodesic motion of massive particles, the effective potential, and the thermal properties such as the radiated energy flux, luminosity, and the temperature profile of the accretion disk around the $\kappa$-deformed RGI-Schwarzschild black hole. Our study shows that when non-commutativity is combined with the RGI framework, the effects produce a noticeable deviation from the classical Schwarzschild case. In particular, for small values of the deformation parameter, we observe an increase in the peak energy flux and the temperature of the accretion disk. This suggests that quantum gravity corrections enhance the disk's radiative efficiency, especially in the inner regions closer to the black hole.

Figures

Figures reproduced from arXiv: 2507.13056 by the authors.

Figure 1
Figure 1. The plot shows the comparison of the improved Schwarzschild metric [PITH_FULL_IMAGE:figures/full_fig_p009_1.png] view at source ↗
Figure 2
Figure 2. The plot shows the geodesic motion of a massive test particle around the Schwarzschild black [PITH_FULL_IMAGE:figures/full_fig_p011_2.png] view at source ↗
Figure 3
Figure 3. The plot shows the variation of the effective potential [PITH_FULL_IMAGE:figures/full_fig_p014_3.png] view at source ↗
Figures from the paper (6 more)
Figure 4
Figure 4. Figure 4: The plot shows the variation of the specific angular momentum [PITH_FULL_IMAGE:figures/full_fig_p015_4.png]
Figure 5
Figure 5. Figure 5: The plot shows the variation of the angular velocity [PITH_FULL_IMAGE:figures/full_fig_p016_5.png]
Figure 6
Figure 6. Figure 6: The plot shows the variation of the effective mass [PITH_FULL_IMAGE:figures/full_fig_p017_6.png]
Figure 7
Figure 7. Figure 7: The plot shows the variation of the energy flux [PITH_FULL_IMAGE:figures/full_fig_p020_7.png]
Figure 8
Figure 8. Figure 8: The plot shows the variation of the differential luminosity [PITH_FULL_IMAGE:figures/full_fig_p021_8.png]
Figure 9
Figure 9. Figure 9: The plot shows the variation of the accretion disk temperature [PITH_FULL_IMAGE:figures/full_fig_p022_9.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. Influence of the external electromagnetic field on the properties of the Novikov-Thorne accretion disk in Kerr spacetime

    gr-qc 2025-07 reject novelty 5.0 of 10

    A numerical study finds that a magnetic field aligned with a Kerr black hole's spin boosts the Novikov-Thorne disk's flux, temperature, and luminosity, with a claimed detectable threshold near 1e-9 T for a 10^6 solar ...

Reference graph

Works this paper leans on

53 extracted references · 53 canonical work pages · cited by 1 Pith paper

  1. [1]

    Hoyle and R

    F. Hoyle and R. A. Lyttleton,Proc. Camb. Philos. Soc.35, 405 (1939)

  2. [2]

    Bondi, F

    H. Bondi, F. Hoyle,Mon. Not. R. Astron. Soc.104, 273 (1944); H. Bondi,Mon. Not. R. Astron. Soc.112, 195 (1952)

  3. [3]

    Michel,Astrophys

    F.C. Michel,Astrophys. Space Sci.15, 153 (1972)

  4. [4]

    Begelman,Astron

    M. Begelman,Astron. Astrophys.70, 583 (1978)

  5. [5]

    Petrich, S.L

    L.I. Petrich, S.L. Shapiro, S.A. Teukolsky,Phys. Rev. Lett.60, 1781 (1988)

  6. [6]

    P. Mach, E. Malec,Phys. Rev. D88, 084055 (2013)

  7. [7]

    Jamil, M.A

    M. Jamil, M.A. Rashid, A. Qadir,Eur. Phys. J. C58, 325 (2008)

  8. [8]

    John, S.G

    A.J. John, S.G. Ghosh, S.D. Maharaj,Phys. Rev. D88, 104005 (2013)

Show all 53 references
  1. [9]

    Ganguly, S.G

    A. Ganguly, S.G. Ghosh, S.D. Maharaj,Phys. Rev. D90, 064037 (2014)

  2. [10]

    Babichev, S

    E. Babichev, S. Chernov, V. Dokuchaev, Yu. Eroshenko,Phys. Rev. D78, 104027 (2008)

  3. [11]

    Shu, J.-H

    Y.-H. Shu, J.-H. Huang,Physics Letters B864, 139411 (2025)

  4. [12]

    Bhattacharyya, A

    S. Bhattacharyya, A. V. Thampan, I. Bombaci,Astron. Astrophys.372, 925 (2001)

  5. [13]

    Torres,Nucl

    D. Torres,Nucl. Phys. B626, 377 (2002)

  6. [14]

    Y.-F. Yuan, R. Narayan, M. J. Rees,The Astrophysical Journal606, 1112 (2004)

  7. [15]

    Weinberg,Cambridge University Press, 790–831 (1979)

    S. Weinberg,Cambridge University Press, 790–831 (1979)

  8. [16]

    Percacci,Cambridge University Press, 111–128 (2009)

    R. Percacci,Cambridge University Press, 111–128 (2009)

  9. [17]

    Yang,Physical Review D92, 084011 (2015)

    R. Yang,Physical Review D92, 084011 (2015)

  10. [18]

    Zuluaga, L.A

    F.H. Zuluaga, L.A. Sanchez,Eur. Phys. J. C81, 840 (2021)

  11. [19]

    M. R. Douglas, N. A. Nekrasov,Rev. Mod. Phys.73, 977 (2001)

  12. [20]

    R. J. Szabo,Phys. Rep.378, 207 (2003)

  13. [21]

    Doplicher, K

    S. Doplicher, K. Fredenhagen, J. E. Roberts,Phys. Lett. B331, 39 (1994); S. Doplicher, K. Freden-hagen, J. E. Roberts,Commun. Math. Phys.172, 187 (1995)

  14. [22]

    Gangopadhyay, B

    S. Gangopadhyay, B. Paik, R. Mandal,Internat. J. Modern Phys. A33, 1850084 (2018)

  15. [23]

    Harikumar, T

    E. Harikumar, T. Juric and S. Meljanac,Phys. Rev. D86, 045002 (2012)

  16. [24]

    Chaichian, P

    M. Chaichian, P. P. Kulish, K. Nishijima and A. Tureanu,Phys. Lett. B604, 98 (2004); M. Chaichian, A. Tureanu, G. Zet,Phys. Lett. B660, 573 (2008)

  17. [25]

    Meljanac and M

    S. Meljanac and M. Stojic,Eur. Phys. J. C47, 531 (2006)

  18. [26]

    Lukierski, A

    J. Lukierski, A. Nowicki, and H. Ruegg,Phys. Lett. B293, 344 (1992)

  19. [27]

    Daszkiewicz, J

    M. Daszkiewicz, J. Lukierski and M. WoronowiczPhys. Rev. D77, 105007 (2008)

  20. [28]

    Harikumar and N

    E. Harikumar and N. S. Zuhair,Int. J. Mod. Phys. A32, 1750072 (2017)

  21. [29]

    Harikumar and N

    E. Harikumar and N. S. Zuhair,J. Phys. Commun.2, 035016 (2018). 24

  22. [30]

    K. S. Gupta, E. Harikumar, T. Juric, S. Meljanac and A. Samsarov,Adv. High Energy Phys. 2014, 139172 (2014); K. S. Gupta, E. Harikumar, T. Juri´ c, S. Meljanac and A. Samsarov,JHEP 2015, 25 (2015)

  23. [31]

    Bhanu Kiran, E

    S. Bhanu Kiran, E. Harikumar, V. Rajagopal,Mod. Phys. Lett. A34, 1950116 (2019)

  24. [32]

    Kumar, S

    D. Kumar, S. K. Panja, A. Saha and S. Sanyal,Mod. Phy. Lett. A40, 2550037 (2025)

  25. [33]

    Dimitrijevic, L

    M. Dimitrijevic, L. Jonke, L. Moller, E. Tsouchnika, J. Wess, M. Wohlgenannt,Eur. Phys. J. C 31, 129 (2003)

  26. [34]

    Meljanac, S

    S. Meljanac, S. Kresic-Juric, M. Stojic,Eur. Phys. J. C51, 229 (2007)

  27. [35]

    Harikumar, T

    E. Harikumar, T. Juric and S. Meljanac,Phys. Rev. D84, 085020 (2011)

  28. [36]

    Kovacevic and S

    D. Kovacevic and S. Meljanac,J. Phys. A: Math. Theor.45, 135208 (2012)

  29. [37]

    Niedermaier,Class

    M. Niedermaier,Class. Quant. Grav.24, R171 (2007)

  30. [38]

    D. F. Litim,Phil.Trans.Roy.Soc.Lond. A369, 2759 (2011)

  31. [39]

    Falls, C.R

    K. Falls, C.R. King, D.F. Litim, K. Nikolakopoulos, C. Rahmede,Phys. Rev. D97, 086006 (2018); K.G. Falls, D.F. Litim, J. Schr¨ oder, Phys. Rev. D99, 126015 (2019)

  32. [40]

    Benedetti, P.F

    D. Benedetti, P.F. Machado, F. Saueressig,Mod. Phys. Lett. A24, 2233 (2009)

  33. [41]

    Cai, D.A

    Y.-F. Cai, D.A. Easson,JCAP09, 002 (2010)

  34. [42]

    Bonanno and M

    A. Bonanno and M. Reuter,Phys. Rev. D62, 043008 (2000)

  35. [43]

    Bjerrum-Bohr, J

    N. Bjerrum-Bohr, J. F. Donoghue, and B. R. Holstein,Phys. Rev. D67, 084033 (2003)

  36. [44]

    Hobson, G.P

    M.P. Hobson, G.P. Efstathiou, A.N. Lasenby,Cambridge University Press(2006)

  37. [45]

    Kaplane,JETP19, 951 (2015)

    S.A. Kaplane,JETP19, 951 (2015)

  38. [46]

    Page, K.S

    D.N. Page, K.S. Thorne,Astrophys. J.191, 499 (1974)

  39. [47]

    Pringle, and M.J

    J.E. Pringle, and M.J. Rees,Astron. Astrophys.21, 1 (1972)

  40. [48]

    Thorne,Astrophys

    K.S. Thorne,Astrophys. J.191, 507 (1974)

  41. [49]

    Novikov, K.S

    D. Novikov, K.S. Thorne, edited by C. DeWitt, B. DeWitt,Gordon and Breach, New York,343, (1973)

  42. [50]

    Shakura, R.A

    N.I. Shakura, R.A. Sunyaev,Astron. Astrophys.24, 337 (1973)

  43. [51]

    Abbas, H

    G. Abbas, H. Rehman, M. Usama, T. Zhu,Eur. Phys. J. C83, 422 (2023)

  44. [52]

    S. M. Carroll, Spacetime and Geometry: An Introduction to General Relativity,Addison Wesley (2004)

  45. [53]

    P. S. Joshi, D. Malafarina, R. Narayan,Class. Quantum Grav.31, 015002 (2014). 25

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.