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arxiv: 2606.05135 · v2 · pith:TFVHJZ53new · submitted 2026-06-03 · 🌀 gr-qc

Hawking Temperatures and Radiation Estimates for Dilaton--de Sitter Black Holes

Pith reviewed 2026-06-28 05:09 UTC · model grok-4.3

classification 🌀 gr-qc
keywords dilaton black holesde Sitter spacetimeHawking temperatureblack hole thermodynamicscosmological constantradiation estimatesgreybody factors
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The pith

Different Hawking temperature prescriptions for dilaton-de Sitter black holes alter radiation power estimates by one to two orders of magnitude.

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

The paper compares several definitions of Hawking temperature for charged dilaton black holes with positive cosmological constant using the Gao-Zhang solution. These include the standard surface-gravity temperature, the Bousso-Hawking normalized version, and effective temperatures constructed from the black-hole and cosmological horizons. For representative parameters, the Bousso-Hawking choice boosts a simple Stefan-Boltzmann power estimate by one to two orders of magnitude over the unnormalized surface-gravity temperature, while an entropy-sum temperature suppresses it. The work highlights how the dilaton and the choice of normalization both affect radiation calculations in spacetimes without global thermal equilibrium.

Core claim

The Gao-Zhang dilaton-de Sitter black hole solution yields inequivalent Hawking temperatures under different prescriptions, with the Bousso-Hawking prescription enhancing Stefan-Boltzmann radiation estimates by one to two orders of magnitude and the entropy-sum effective temperature suppressing them, relative to the standard surface-gravity temperature.

What carries the argument

Comparison of temperature prescriptions (surface-gravity temperature, Bousso-Hawking temperature, and entropy-sum effective temperatures) applied to the four-dimensional Gao-Zhang solution in Einstein-Maxwell-dilaton theory.

Load-bearing premise

The temperature prescriptions developed for Schwarzschild-de Sitter black holes remain the appropriate and inequivalent definitions when a dilaton field is added to the theory.

What would settle it

An explicit computation of the greybody factors for the Gao-Zhang black hole that demonstrates the emitted power does not differ by one to two orders of magnitude across the temperature prescriptions.

read the original abstract

Charged dilaton black holes with a positive cosmological constant provide a useful arena in which to test how scalar hair modifies semiclassical physics in a spacetime with two Killing horizons. The Gao--Zhang solution realizes such a geometry in Einstein--Maxwell--dilaton theory by replacing a single Liouville potential, which is insufficient for asymptotically de Sitter boundary conditions, by a three-Liouville dilaton potential. Although the solution and several of its perturbative and optical properties have been studied, its temperature and heat capacity have not been examined through the same range of temperature prescriptions commonly considered for Schwarzschild--de Sitter black holes, where the absence of global thermal equilibrium motivates several inequivalent temperature definitions. We present this temperature-prescription comparison for the four-dimensional, string-coupling member of the Gao--Zhang family. We compare the standard surface-gravity temperature, the Bousso--Hawking-normalized temperature, and two effective temperatures built from the black-hole and cosmological horizons. The dilaton changes the areal radius, entropy, photon-sphere condition, and greybody problem, while the de Sitter normalization ambiguity changes radiation estimates by powers of the redshift factor. For representative parameters, the Bousso--Hawking prescription can enhance a Stefan--Boltzmann estimate of the black-hole power by one to two orders of magnitude relative to the unnormalized surface-gravity prescription, whereas the entropy-sum effective temperature can suppress the same estimate. These results identify a concrete gap in the thermodynamics of dilaton--de Sitter black holes and provide a roadmap for a full greybody-factor calculation.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

1 major / 0 minor

Summary. The manuscript compares four temperature prescriptions (standard surface-gravity, Bousso-Hawking normalized, and two effective temperatures from the black-hole and cosmological horizons) for the four-dimensional Gao-Zhang charged dilaton black hole in de Sitter spacetime. It reports that, for representative parameters, the Bousso-Hawking prescription enhances a Stefan-Boltzmann estimate of the black-hole power by one to two orders of magnitude relative to the unnormalized surface-gravity prescription, while the entropy-sum effective temperature suppresses the estimate. The work identifies a gap in the thermodynamics of dilaton-de Sitter black holes and provides a roadmap for a full greybody-factor calculation.

Significance. If the temperature prescriptions remain valid and inequivalent once the dilaton is included, the results demonstrate that scalar hair and the choice of normalization/redshift factors can alter radiation estimates by orders of magnitude in these spacetimes. The explicit comparison for representative parameters and the identification of the concrete gap are strengths; the suggestion of a roadmap for greybody calculations is also useful.

major comments (1)
  1. Abstract: The central numerical claim (Bousso-Hawking enhances Stefan-Boltzmann power by 1-2 orders; entropy-sum suppresses it) is load-bearing on the assumption that the four SdS-motivated temperature definitions remain the appropriate and inequivalent choices for the Gao-Zhang solution. The manuscript invokes the absence of global thermal equilibrium as motivation but supplies no explicit check that this motivation (or the interpretation of the normalization/redshift factors) survives the three-Liouville potential and the modifications to areal radius, entropy, and photon-sphere structure induced by the dilaton. This must be addressed before the order-of-magnitude shifts can be interpreted as physical effects rather than artifacts of transplanted definitions.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the detailed report and the opportunity to clarify the assumptions underlying our temperature comparisons. We address the major comment below and outline the revisions we will make.

read point-by-point responses
  1. Referee: Abstract: The central numerical claim (Bousso-Hawking enhances Stefan-Boltzmann power by 1-2 orders; entropy-sum suppresses it) is load-bearing on the assumption that the four SdS-motivated temperature definitions remain the appropriate and inequivalent choices for the Gao-Zhang solution. The manuscript invokes the absence of global thermal equilibrium as motivation but supplies no explicit check that this motivation (or the interpretation of the normalization/redshift factors) survives the three-Liouville potential and the modifications to areal radius, entropy, and photon-sphere structure induced by the dilaton. This must be addressed before the order-of-magnitude shifts can be interpreted as physical effects rather than artifacts of transplanted definitions.

    Authors: We agree that an explicit justification is warranted. The absence of global thermal equilibrium follows from the two Killing horizons having unequal surface gravities, which holds for the Gao-Zhang metric because the three-Liouville potential permits distinct horizon locations without forcing κ_BH = κ_C. We will add a short calculation in Section 2 (or a new subsection) verifying that κ_BH eq κ_C for the representative parameter sets used in the numerics. The Bousso-Hawking normalization is fixed by the value of the timelike Killing vector at a static observer between the horizons; this construction depends only on the existence of the Killing vector and the metric component g_tt and is insensitive to the specific form of the dilaton potential. The areal-radius and entropy modifications affect the Stefan-Boltzmann prefactor but not the temperature definitions themselves. Photon-sphere shifts influence greybody factors, which the manuscript already flags as future work. The reported order-of-magnitude differences are therefore comparisons under these standard horizon-based prescriptions rather than final physical luminosities; we will revise the abstract and introduction to state this scope explicitly. These additions will be incorporated in the revised manuscript. revision: partial

Circularity Check

0 steps flagged

No circularity: standard prescriptions applied to existing solution

full rationale

The manuscript applies four established temperature definitions (surface-gravity, Bousso-Hawking normalization, and two entropy-sum effective temperatures) drawn from prior Schwarzschild-de Sitter literature to the Gao-Zhang dilaton-de Sitter metric. The abstract and description contain no equations in which a temperature or power is defined in terms of itself, no fitted parameters renamed as predictions, and no load-bearing self-citation chains that reduce the central numerical comparison to an input. The reported order-of-magnitude shifts in Stefan-Boltzmann estimates arise from direct substitution of the new metric functions into the pre-existing formulas; the derivation chain therefore remains independent of the target results.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Abstract only; no explicit free parameters, axioms, or invented entities are stated beyond reliance on the pre-existing Gao-Zhang solution and standard temperature definitions from the Schwarzschild-de Sitter literature.

axioms (1)
  • domain assumption The Gao-Zhang solution with three-Liouville potential realizes the desired charged dilaton-de Sitter geometry.
    Taken as given in the abstract as the arena for the temperature comparison.

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discussion (0)

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Reference graph

Works this paper leans on

34 extracted references · 29 canonical work pages

  1. [1]

    Black Holes and Membranes in Higher-Dimensional Theories with Dilaton Fields.Nucl

    Gibbons, G.W.; Maeda, K. Black Holes and Membranes in Higher-Dimensional Theories with Dilaton Fields.Nucl. Phys. B1988,298, 741–775. https://doi.org/10.1016/0550-3213(88)90006-5

  2. [2]

    Charged Black Holes in String Theory.Phys

    Garfinkle, D.; Horowitz, G.T.; Strominger, A. Charged Black Holes in String Theory.Phys. Rev. D1991,43, 3140–

  3. [3]

    https://doi.org/10.1103/PhysRevD.45.3888; Erratum inPhys. Rev. D1992,45, 3888. https://doi.org/10.1103 /PhysRevD.43.3140

  4. [4]

    Dilaton Black Holes in de Sitter or Anti-de Sitter Universe.Phys

    Gao, C.J.; Zhang, S.N. Dilaton Black Holes in de Sitter or Anti-de Sitter Universe.Phys. Rev. D2004,70, 124019. https://doi.org/10.1103/PhysRevD.70.124019

  5. [5]

    Higher-Dimensional Dilaton Black Holes with Cosmological Constant.Phys

    Dehghani, M.H. Higher-Dimensional Dilaton Black Holes with Cosmological Constant.Phys. Lett. B2005,605, 185–189. https://doi.org/10.1016/j.physletb.2004.11.030. https://doi.org/10.53941/ijgtp.2026.200002 10 of 12 Ertugay Int. J. Gravit. Theor . Phys.2026,2(2), 2

  6. [6]

    Particle Motion and Gravitational Lensing in the Metric of a Dilaton Black Hole in a de Sitter Universe.Gen

    Mukherjee, N.; Majumdar, A.S. Particle Motion and Gravitational Lensing in the Metric of a Dilaton Black Hole in a de Sitter Universe.Gen. Relativ. Gravit.2007,39, 583–600. https://doi.org/10.1007/s10714-007-0407-5

  7. [7]

    Quasinormal Modes of Dilaton-de Sitter Black Holes: Scalar Perturbations.Gen

    Fernando, S. Quasinormal Modes of Dilaton-de Sitter Black Holes: Scalar Perturbations.Gen. Relativ. Gravit.2016,48, 24. https://doi.org/10.1007/s10714-016-2020-y

  8. [8]

    Asymptotic Decay and Quasinormal Frequencies of Scalar Fields in a Dilaton-de Sitter Black-Hole Geometry.Eur

    Dubinsky, A.; Zinhailo, A.F. Asymptotic Decay and Quasinormal Frequencies of Scalar Fields in a Dilaton-de Sitter Black-Hole Geometry.Eur . Phys. J. C2024,84, 847. https://doi.org/10.1140/epjc/s10052-024-13206-6

  9. [9]

    Thermodynamics of Charged Topological Dilaton Black Holes.Phys

    Sheykhi, A. Thermodynamics of Charged Topological Dilaton Black Holes.Phys. Rev. D2007,76, 124025. https://doi.org/10 .1103/PhysRevD.76.124025

  10. [10]

    Thermodynamic Instability of Charged Dilaton Black Holes in AdS Spaces

    Sheykhi, A.; Dehghani, M.H.; Hendi, S.H. Thermodynamic Instability of Charged Dilaton Black Holes in AdS Spaces. Phys. Rev. D2010,81, 084040. https://doi.org/10.1103/PhysRevD.81.084040

  11. [11]

    Constructing Black Holes in Einstein–Maxwell–Scalar Theory.Class

    Yu, S.; Qiu, J.; Gao, C. Constructing Black Holes in Einstein–Maxwell–Scalar Theory.Class. Quantum Grav.2021,38, 105006. https://doi.org/10.1088/1361-6382/abf2f5

  12. [12]

    P-V Criticality of Higher Dimensional Charged Topological Dilaton de Sitter Black Holes.Phys.Rev.D2014,90, 064018.https://doi.org/10.1103/PhysRevD.90.064018

    Zhao, Z.; Zhang, L.C.; Ma, M.S.; Zhao, R. P-V Criticality of Higher Dimensional Charged Topological Dilaton de Sitter Black Holes.Phys.Rev.D2014,90, 064018.https://doi.org/10.1103/PhysRevD.90.064018

  13. [13]

    Pair Creation of Black Holes During Inflation.Phys

    Bousso, R.; Hawking, S.W. Pair Creation of Black Holes During Inflation.Phys. Rev. D1996,54, 6312. https://doi.org /10.1103/PhysRevD.54.6312

  14. [14]

    (Anti-)Evaporation of Schwarzschild–de Sitter Black Holes.Phys

    Bousso, R.; Hawking, S.W. (Anti-)Evaporation of Schwarzschild–de Sitter Black Holes.Phys. Rev. D1998,57, 2436. https://doi.org/10.1103/PhysRevD.57.2436

  15. [15]

    Effective Temperatures and Radiation Spectra for a Higher-Dimensional Schwarzschild–de Sitter Black Hole.Phys

    Kanti, P.; Pappas, T. Effective Temperatures and Radiation Spectra for a Higher-Dimensional Schwarzschild–de Sitter Black Hole.Phys. Rev. D2017,96, 024038. https://doi.org/10.1103/PhysRevD.96.024038

  16. [16]

    Schwarzschild–de Sitter Spacetime: The Role of Temperature in the Emission of Hawking Radiation

    Pappas, T.; Kanti, P. Schwarzschild–de Sitter Spacetime: The Role of Temperature in the Emission of Hawking Radiation. Phys. Lett. B2017,775, 140–146. https://doi.org/10.1016/j.physletb.2017.10.058

  17. [17]

    Hawking Radiation Spectra for Scalar Fields by a Higher-Dimensional Schwarzschild–de Sitter Black Hole.Phys

    Pappas, T.; Kanti, P.; Pappas, N. Hawking Radiation Spectra for Scalar Fields by a Higher-Dimensional Schwarzschild–de Sitter Black Hole.Phys. Rev. D2016,94, 024035. https://doi.org/10.1103/PhysRevD.94.024035

  18. [18]

    Hamilton-Jacobi and Schr¨ odinger Separable Solutions of Einstein’s Equations,

    Carter, B. Hamilton-Jacobi and Schrodinger Separable Solutions of Einstein’s Equations.Commun. Math. Phys.1968,10, 280–310. https://doi.org/10.1007/BF03399503

  19. [19]

    Axisymmetric Black Holes Allowing for Separation of Variables in the Klein- Gordon and Hamilton-Jacobi Equations.Phys

    Konoplya, R.A.; Stuchl´ık, Z.; Zhidenko, A. Axisymmetric Black Holes Allowing for Separation of Variables in the Klein- Gordon and Hamilton-Jacobi Equations.Phys. Rev. D2018,97, 084044. https://doi.org/10.1103/PhysRevD.97.084044

  20. [20]

    Bulk and Brane Decay of a (4 +n)-Dimensional Schwarzschild-de-Sitter Black Hole: Scalar Radiation.Phys

    Kanti, P.; Grain, J.; Barrau, A. Bulk and Brane Decay of a (4 +n)-Dimensional Schwarzschild-de-Sitter Black Hole: Scalar Radiation.Phys. Rev. D2005,71, 104002. https://doi.org/10.1103/PhysRevD.71.104002

  21. [21]

    Greybody Factors for Nonminimally Coupled Scalar Fields in Schwarzschild–de Sitter Spacetime.Phys

    Crispino, L.C.B.; Higuchi, A.; Oliveira, E.S.; et al. Greybody Factors for Nonminimally Coupled Scalar Fields in Schwarzschild–de Sitter Spacetime.Phys. Rev. D2013,87, 104034. https://doi.org/10.1103/PhysRevD.87.104034

  22. [22]

    Particle Emission Rates from a Black Hole

    Page, D.N. Particle Emission Rates from a Black Hole. II. Massless Particles from a Rotating Hole.Phys. Rev. D1976,14,

  23. [23]

    https://doi.org/10.1103/PhysRevD.14.3260

  24. [24]

    Particle Emission Rates from a Black Hole: Massless Parti- cles from an Uncharged, Nonrotating Hole,

    Page, D.N. Particle Emission Rates from a Black Hole: Massless Particles from an Uncharged, Nonrotating Hole.Phys. Rev. D1976,13, 198. https://doi.org/10.1103/PhysRevD.13.198

  25. [25]

    GrayHawk: A Public Code for Calculating the Gray Body Factors of Massless Fields Around Spherically Symmetric Black Holes.Phys

    Calz´a, M. GrayHawk: A Public Code for Calculating the Gray Body Factors of Massless Fields Around Spherically Symmetric Black Holes.Phys. Dark Univ.2025,48, 101900. https://doi.org/10.1016/j.dark.2025.101900

  26. [26]

    Analytic Expressions for Quasinormal Modes and Grey-Body Factors in the Eikonal Limit and Beyond.Class

    Konoplya, R.A.; Zhidenko, A. Analytic Expressions for Quasinormal Modes and Grey-Body Factors in the Eikonal Limit and Beyond.Class. Quantum Grav.2023,40, 245005. https://doi.org/10.1088/1361-6382/ad0a52

  27. [27]

    Black Hole Normal Modes: A WKB Approach

    Iyer, S.; Will, C.M. Black Hole Normal Modes: A WKB Approach. 1. Foundations and Application of a Higher Order WKB Analysis of Potential Barrier Scattering.Phys. Rev. D1987,35, 3621. https://doi.org/10.1103/PhysRevD.35.3621

  28. [28]

    Grey-Body Factors and Absorption Cross-Sections of Scalar and Dirac Fields in the Vicinity of Dilaton-de Sitter Black Hole.F ortsch

    L¨utf¨uo˘glu, B.C. Grey-Body Factors and Absorption Cross-Sections of Scalar and Dirac Fields in the Vicinity of Dilaton-de Sitter Black Hole.F ortsch. Phys.2026,74, e70074. https://doi.org/10.1002/prop.70074

  29. [29]

    Hawking Radiation and Greybody Factors of Test Scalar and Electromagnetic Fields on Asymptotically Flat Pure Lovelock Black Holes.arXiv2026, arXiv:2605.09756

    Tan, J. Hawking Radiation and Greybody Factors of Test Scalar and Electromagnetic Fields on Asymptotically Flat Pure Lovelock Black Holes.arXiv2026, arXiv:2605.09756

  30. [30]

    A First-Order Eikonal Framework for Quasinormal Modes, Shad- ows, Strong Lensing, and Grey-Body Factors in a Scalarized Black-Hole Metric.Ann

    L¨utf¨uo˘glu, B.C.; Rayimbaev, J.; Murodov, S.; et al. A First-Order Eikonal Framework for Quasinormal Modes, Shad- ows, Strong Lensing, and Grey-Body Factors in a Scalarized Black-Hole Metric.Ann. Phys.2026,491, 170514. https://doi.org/10.1016/j.aop.2026.170514

  31. [31]

    Long-Lived Quasinormal Modes and Gray-Body Factors of Black Holes and Wormholes in Dark Matter Inspired Weyl Gravity.Eur

    L¨utf¨uo˘glu, B.C. Long-Lived Quasinormal Modes and Gray-Body Factors of Black Holes and Wormholes in Dark Matter Inspired Weyl Gravity.Eur . Phys. J. C2025,85, 486. https://doi.org/10.1140/epjc/s10052-025-14210-0

  32. [32]

    Massive Scalar Quasinormal Modes, Greybody Factors, and Absorption Cross Section of a Parity-Symmetric Beyond-Horndeski Black Hole.arXiv2026, arXiv:2605.11013

    Bolokhov, S.V . Massive Scalar Quasinormal Modes, Greybody Factors, and Absorption Cross Section of a Parity-Symmetric Beyond-Horndeski Black Hole.arXiv2026, arXiv:2605.11013

  33. [33]

    Scattering of Scalar, Electromagnetic, and Dirac Fields in an Asymptotically Flat Regular Black Hole https://doi.org/10.53941/ijgtp.2026.200002 11 of 12 Ertugay Int

    Bolokhov, S.V . Scattering of Scalar, Electromagnetic, and Dirac Fields in an Asymptotically Flat Regular Black Hole https://doi.org/10.53941/ijgtp.2026.200002 11 of 12 Ertugay Int. J. Gravit. Theor . Phys.2026,2(2), 2 Supported by Primordial Dark Matter.arXiv2026, arXiv:2605.03137

  34. [34]

    Quantum Corrected Black Holes: Testing the Correspondence Between Grey-Body Factors and Quasinormal Modes.Eur

    Skvortsova, M. Quantum Corrected Black Holes: Testing the Correspondence Between Grey-Body Factors and Quasinormal Modes.Eur . Phys. J. C2025,85, 854. https://doi.org/10.1140/epjc/s10052-025-14589-w. https://doi.org/10.53941/ijgtp.2026.200002 12 of 12