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REVIEW 3 major objections 6 minor 82 references

Fine-tuning in mixed Dark Matter models with Primordial Black Hole relics

T0 review · 3 major / 6 minor · reviewed 2026-08-12 · deepseek-v4-flash

Pith's one-line read The tuning of PBH-relic dark matter lives in the black hole formation rate, not in the particle dark matter candidate.

desk verdict Fine-tuning in mixed DM with PBH relics is dominated by P_ζ sensitivity as claimed for WIMP and freeze-in, but the axion extension is asserted without numbers; worth publishing after major revision. read the letter →

arxiv 2608.10977 v1 pith:5ZHQIDT3 submitted 2026-08-11 astro-ph.CO

classification astro-ph.CO
keywords primordialblackholesdarkmatterfine-tuningHawkingevaporationPlanck-massrelicscurvaturepowerspectrumQCDaxionfreeze-in
topics Dark Matter
open problems Dark Matter
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

The paper asks how much the early universe must be tuned for a three-component dark-matter sector—Planck-mass relics left when tiny primordial black holes evaporate, particles emitted during that evaporation, and an independently produced dark-matter component—to add up to the observed $\Omega_{\rm DM}$. It finds that the dominant fine-tuning always sits in the black-hole formation step: the initial PBH fraction $\beta(P_\zeta)=\mathrm{Erfc}(\delta_c/\sqrt{2P_\zeta})$ depends exponentially on the primordial curvature power spectrum $P_\zeta$, so the Barbieri–Giudice sensitivity $\Delta_{P_\zeta}\sim 10$–$100$ outweighs sensitivities to particle masses, cross sections, or evaporation details. This holds whether the third component is a thermal WIMP, a freeze-in particle, or a QCD axion. An early PBH-dominated era dilutes pre-existing abundances and locally erases the $\beta_i$ dependence, but the universe still needs a large tuned perturbation amplitude to reach that era. Supercooled phase transitions and collapsing domain walls replace the inflationary exponential with their own exponentials, leading the paper to conclude that an order-unity PBH relic abundance is hard to motivate naturally.

What carries the argument

The central object is the Press–Schechter formation fraction $\beta(P_\zeta)=\mathrm{Erfc}(\delta_c/\sqrt{2P_\zeta})$ with collapse threshold $\delta_c\simeq0.45$, which converts the primordial curvature power spectrum into an initial PBH abundance. Because $\beta$ depends exponentially on $P_\zeta$, the Barbieri–Giudice measure $\Delta_{P_\zeta}=|\partial\ln\Omega/\partial\ln P_\zeta|$ becomes the dominant sensitivity in the tripartite DM abundance, while parameters entering through power laws, such as $m_\chi$, $\langle\sigma v\rangle$, and $M_{\rm PBH}$, give $O(1)$ or smaller measures. The early-PBH-dominated branch is governed by formulas in which final relic and evaporated yields become independent of $\beta_i$ after entropy injection, so the local measure gives $\Delta_{\beta_i}=0$ there, but the same large $P_\zeta$ amplitude is still needed to trigger the domination epoch.

What would settle it

A direct calculation of the PBH formation fraction with non-Gaussian primordial perturbations, or a numerical-relativity determination of the collapse threshold as a function of peak height, would settle the quantitative claim: if $\beta(P_\zeta)$ is not erfc-like over the relevant amplitude range, the reported hierarchy $\Delta_{P_\zeta}\sim10$–$100$ versus $O(1)$ particle parameters would not survive.

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Extended reading notes

Core claim

The paper's central claim is that in a tripartite dark-matter model with Planck-mass PBH relics, the total abundance's parameter sensitivity is dominated by the PBH formation mechanism rather than by the particle candidate or evaporation physics. Across WIMP freeze-out, freeze-in, and QCD axion misalignment, the qualitative hierarchy is unchanged: the primordial curvature power spectrum $P_\zeta$ gives the largest Barbieri–Giudice measure because the formation fraction $\beta(P_\zeta)=\mathrm{Erfc}(\delta_c/\sqrt{2P_\zeta})$ is exponentially sensitive to $P_\zeta$. Even when an early PBH-dominated era makes the final relic and evaporated abundances independent of the initial PBH fraction $\beta_i$, the required initial perturbation amplitude remains a tuned input. Alternative formation channels such as supercooled phase transitions and domain-wall collapse do not remove the exponential; they transfer it to parameters like $\beta/H$ or $\alpha_{\rm ann}$. The paper therefore concludes that a natural realization of an order-unity PBH relic abundance is difficult to motivate.

Load-bearing premise

The quantitative hierarchy assumes the Gaussian Press–Schechter relation $\beta(P_\zeta)=\mathrm{Erfc}(\delta_c/\sqrt{2P_\zeta})$ with $\delta_c\simeq0.45$ and that the local Barbieri–Giudice sensitivity is the right way to judge naturalness; if non-Gaussianities change the functional form, or a global prior-based measure is used, the numerical conclusions can shift.

Editorial extensions

If this is right

  • The observed DM abundance in these models is most sensitive to the amplitude of primordial curvature perturbations, so a measurement or bound on $P_\zeta$ at PBH scales directly constrains how tuned the model must be.
  • Choosing a different particle DM candidate—WIMP freeze-out, freeze-in, or QCD axion—does not change the qualitative hierarchy of fine-tuning parameters.
  • A PBH-dominated era makes the final relic abundance insensitive to the initial PBH fraction, but the large initial perturbation amplitude needed to reach that era remains a required tuned input.
  • If PBH formation instead proceeds through supercooled phase transitions or domain-wall collapse, the exponential sensitivity reappears in $\beta/H$ or $\alpha_{\rm ann}$, so the naturalness problem is shifted rather than solved.
  • A natural model of PBH relics must either produce a large curvature perturbation peak without exponential parameter dependence or invoke a formation channel whose exponential is controlled by a parameter that can be order-one without tuning.

Reading between the lines

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

  • Editorial extension: the paper itself notes that the Barbieri–Giudice measure is local and not reparameterization invariant; a global, prior-based naturalness measure would likely make the early-domination branch look even more tuned than the local $\Delta=0$ suggests, because most of the logarithmic prior on $P_\zeta$ produces no PBH domination at all.
  • Editorial extension: the same machinery could be applied to any scenario where the PBH abundance is exponentially sensitive to an underlying amplitude, such as power spectra generated by spectator fields or cosmic defects, to compare their naturalness on a common footing.
  • Editorial extension: a concrete test of the hierarchy would be to compute $\beta(P_\zeta)$ including primordial non-Gaussianity; if the functional form changes significantly, the reported values of $\Delta_{P_\zeta}$ would need revision even if a large sensitivity remains.
  • Editorial extension: future gravitational-wave constraints on the small-scale curvature power spectrum, for example from pulsar timing arrays or space-based interferometers, could locate the required peak amplitude and directly test whether it falls in the fine-tuned regime this paper identifies.
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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. This paper studies the sensitivity of the total dark-matter abundance in a tripartite model consisting of (i) Planck-mass relics left after PBH evaporation, (ii) particles produced by Hawking evaporation, and (iii) an independently produced component, which is taken to be WIMP freeze-out, freeze-in, or QCD axion misalignment. The authors apply the Barbieri–Giudice measure to parameters such as P_ζ, M_PBH, m_χ, and ⟨σv⟩, and find that in radiation domination the dominant fine-tuning is Δ_Pζ ∼ 10–100 because the Press–Schechter relation β = Erfc(δ_c/√(2P_ζ)) makes the PBH abundance exponentially sensitive to the curvature power spectrum. They argue that an early PBH-dominated phase removes the local sensitivity to β while still requiring a tuned inflationary amplitude, and that alternative formation channels (supercooled phase transitions, domain-wall collapse) transfer the exponential sensitivity to different parameters. The paper concludes that a natural order-unity PBH relic abundance is hard to motivate.

Significance. The central derivation is transparent and the qualitative hierarchy is robust: the functional dependence of β on P_ζ is exponential, and the paper correctly emphasizes that local Barbieri–Giudice measures can miss the global tuning of the inflationary sector. The manuscript is also honest about the known limitations of the BG measure and about the model dependence of the FOPT and domain-wall estimates. However, the quantitative claims for the QCD axion are not backed by any numbers or figure, and several quoted values (Δ_Pζ and Δ_M_PBH) are not reproducible from the text. These issues are fixable and do not overturn the qualitative conclusion.

major comments (3)
  1. [4.1.1] The abstract and the conclusion state that the fine-tuning hierarchy is robust for all three DM candidates considered, 'including the QCD axion.' Section 4.1.1, however, only asserts that 'we found very similar results' and refers to Fig. 3, which shows the thermal-WIMP case; no Barbieri–Giudice values, benchmark parameters, or a figure for the tripartite axion model are provided. Appendix A2 tabulates axion-only sensitivities in non-standard cosmologies but does not compute Δ_Pζ for the full model. Because the total DM fraction in the axion case is f_relic + f_χ + f_axion, the relative size of f_relic directly sets Δ_Pζ, and the paper does not specify this benchmark. Please add a quantitative axion benchmark (e.g., post-inflationary θ_i = π/√3, a chosen m_a, and the relic/evaporation/axion split) and show the resulting Δ_Pζ and the competing measures, either in a table or in a figure analogous to Fig. 3.
  2. [5.1] Equation (5.2) (and the simplified scaling in Eq. (5.4)) gives f_relic ∝ M_PBH^(−3/2) P_coll, so if P_coll is independent of M_PBH, the Barbieri–Giudice measure for M_PBH is 3/2. The text quotes Δ_M_PBH ≃ 0.72, which is not consistent with this scaling. Either the quoted value comes from a different parameterization (e.g., varying M_PBH while keeping the total DM fixed by some relation to the phase-transition temperature) or it is a typo; please state the exact derivation and, if the 3/2 value is the correct one, correct the number. This does not change the qualitative conclusion that the exponential β/H dependence dominates, but the quantitative comparison should be internally consistent.
  3. [3.1] The quantitative fine-tuning values quoted in the text—Δ_Pζ ≃ 10–100 in §3.1, Δ_Pζ ≃ 19–32 in §3.3, and Δ_β/H ≃ 32–69 in §5.1—are given as ranges with no benchmark table. The text fixes m_χ = 100 GeV and f_χ = f_relic, but it does not state the corresponding values of P_ζ, β_i, and the fractional components for the different M_PBH values, nor does it specify how the constraint Ω_total = Ω_DM is imposed. Please provide a table of benchmark points and, where possible, an estimate of the sensitivity of the quoted ranges to δ_c and to the choice of the Press–Schechter threshold; without this the numerical hierarchy cannot be reproduced or compared across the three production mechanisms.
minor comments (6)
  1. [2.2.2] 'regime tof Hawking evaporation' should be 'regime of Hawking evaporation'.
  2. [3.2] 'inequivelant' should be 'inequivalent'.
  3. [Table of Contents] 'Appendex' should be 'Appendix'.
  4. [Equations (1.2) and (7.5)] The coefficient 4×10^(−26)/g in Eq. (7.5) should be reconciled with the 4×10^(−28) quoted in Eq. (1.2); the text should state explicitly that g ≃ 108 is used in the numerical coefficient.
  5. [Figure 3 caption] 'Pζ dominates the dominant fine-tuning' is awkward and should be rephrased, e.g., 'Δ_Pζ is the dominant fine-tuning measure'.
  6. [5.1] The remark that bubble collisions give 'a single exponential suppression … rather than the double exponential dependence' of density-perturbation collapse is misleading; β(P_ζ) is a single exponential in 1/P_ζ, and the double-exponential statement should be clarified or removed.

Circularity Check

0 steps flagged · score 2.0 of 10

No significant circularity: BG measures are derivatives of stated abundance formulas; the self-citation [33] is not load-bearing, though the axion extension is asserted without quantitative support.

full rationale

The paper's derivation chain is not circular. The Barbieri–Giudice measures are computed by differentiating the explicitly stated abundance formulas (Eqs. 2.2, 2.10, 2.15, 3.2, 4.1, 5.1–5.7) with respect to their parameters; no parameter is fitted to reproduce Ω_DM and no derived abundance is reinserted as an input. The central result, Δ_Pζ ≫ Δ_mχ, Δ_⟨σv⟩, follows from the assumed Gaussian Press–Schechter relation β(Pζ)=Erfc(δ_c/√(2Pζ)) given in Section 3 together with frelic ∝ β_i in the RD branch of Eq. (2.2); this is a genuine model implication rather than a restatement of the measure. The self-citation to Ref. [33] in Section 2.1 ('Following Ref. [33], the relic fraction is then given by...') is the only overlap with the authors' prior work, and it is not load-bearing: Eq. (2.2) is a standard relic-abundance formula, and order-one changes to it would not alter the exponential Pζ hierarchy that drives the conclusion. The alternative-formation sections inherit exponential forms from external fits (Refs. [59,77,81]) and then differentiate those forms; that is assumption-following, not circularity. One flagged weakness is missing support rather than circularity: Section 4.1.1 states 'We found very similar results' for the QCD axion tripartite model without presenting the corresponding Δ_Pζ values or a figure, even though the axion fraction itself has no Pζ sensitivity, so the advertised candidate-independence is under-demonstrated for the axion. This affects confidence in robustness, not the logical independence of the derivation.

Assumptions & free parameters 9 free parameters · 8 assumptions · 0 invented entities

The central claim rests on standard cosmology and PBH formation formulas, plus several benchmark choices. The most important axioms are the Gaussian Press-Schechter formation fraction with δ_c=0.45 and the assumption of monochromatic PBHs with negligible accretion. The alternative-formation sections depend on order-one fitted exponents from the cited literature.

free parameters (9)
  • Collapse threshold δ_c = 0.45
    Chosen in Section 3 for the Press-Schechter relation; the exponential sensitivity Δ_Pζ scales with δ_c, so the numerical values depend on this choice.
  • WIMP mass m_χ = 100 GeV
    Benchmark used for WIMP freeze-out in Section 3.1 and Figure 3; affects Δ_mχ and Δ_{⟨σv⟩}, not the dominant Δ_Pζ.
  • WIMP annihilation cross section ⟨σv⟩ = 3×10^-26 cm^3 s^-1
    Benchmark thermal annihilation cross section used in Eq. (2.15) and Figure 3; standard value but chosen by hand.
  • Freeze-in mediator mass M_D = 100 GeV
    Benchmark in Section 3.3; affects the freeze-in abundance and Δ_yD.
  • Internal degrees of freedom of DM particle g_χ = 1
    Section 2.2 states 'we assume g_χ=1 throughout the remainder of this work as a representative benchmark.'
  • Post-inflationary axion initial angle θ_i = π/√3 ≈ 1.81
    Section 4.1; an averaged value over patches, determines the axion fraction.
  • Relic fraction parity condition f_relic = f_χ = 1:1
    Section 2.2.2 and Appendix A1; benchmark for splitting DM fractions; paper argues robustness, but the numerical Δ values in the main text assume this split.
  • Planck-mass relic mass M_Pl = 2.18×10^-5 g
    Section 2.1 assumes evaporation terminates at a Planck-mass remnant; if the relic mass differs, the required β shifts but the qualitative conclusion is unchanged.
  • Order-one coefficients a,b,c,d in FOPT and domain-wall collapse probabilities
    Equations (5.1) and (5.5) use fitting parameters from Gouttenoire et al. [59,81]; values not specified numerically in this paper but affect Δ_{β/H} ~ 32-69 and the domain-wall tuning estimates.
assumptions (8)
  • standard math Standard Friedmann-Robertson-Walker cosmology with radiation domination in the baseline scenario.
    Used throughout Section 2 and Appendix A4 to relate temperature, time, and entropy densities; not proved here.
  • domain assumption Hawking evaporation proceeds with a constant effective number of degrees of freedom g_*H ≈ 108 and terminates at a Planck-mass relic.
    Section 2.1 and Eq. (2.2); the relic existence is a quantum gravity assumption from prior work [30,31,32,33].
  • domain assumption Primordial perturbations are Gaussian and PBH formation follows Press-Schechter with threshold δ_c ≈ 0.45.
    Section 3, β(P_ζ)=Erfc(δ_c/√(2P_ζ)); central to the exponential sensitivity claim.
  • domain assumption The PBH mass distribution is monochromatic and accretion is negligible.
    Section 1 after Eq. (1.1); the paper explicitly states this approximation; affects all relic abundance formulas.
  • standard math WIMP freeze-out occurs in a radiation-dominated era and follows the standard Lee-Weinberg equation with Lambert W solution.
    Section 2.3, Eqs. (2.14)-(2.15); relies on Refs [67,66].
  • domain assumption Freeze-in abundance follows the IR-dominated formula of Hall et al. with a mediator of mass M_D=100 GeV.
    Section 3.3, Eq. (3.2); benchmark mediator mass chosen by hand.
  • domain assumption QCD axion field oscillates in the standard misalignment scenario with post-inflationary initial angle θ_i=π/√3 and relic abundance from Ref [73].
    Section 4.1, Eq. (4.1); the angle choice is a benchmark.
  • domain assumption The collapse probability for PBH formation in first-order phase transitions and domain walls is exponentially suppressed with order-one fitting parameters a,b,c,d as in Eqs. (5.1) and (5.5).
    Section 5; the parameters come from Refs [59,81], and the paper notes the FOPT calculation is still under debate.

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Cite this review

Pith. "Pith review of Fine-tuning in mixed Dark Matter models with Primordial Black Hole relics." pith.science (2026). https://pith.science/paper/5ZHQIDT3

@misc{pith2026260810977,
  author       = {Pith},
  title        = {Pith review of: Fine-tuning in mixed Dark Matter models with Primordial Black Hole relics},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/5ZHQIDT3}},
  note         = {Machine review of arXiv:2608.10977}
}
abstract

We investigate the fine-tuning of a tripartite dark matter (DM) scenario involving ultra-light primordial black holes (PBHs), whose evaporation before Big Bang Nucleosynthesis leaves Planck-mass relics and produces DM particles together with an independently produced DM component. We uniformly evaluate the parameter sensitivity required to reproduce the observed DM abundance, $\Omega_{\rm DM}$. Considering thermal WIMP freeze-out, freeze-in, and QCD axion misalignment, and assuming PBHs form via collapse of perturbations following horizon entry, we find that the fine-tuning is normally dominated by the structure of the PBH relic abundance calculation rather than by the particle DM candidate or the details of PBH evaporation. In radiation-dominated cosmologies, the DM abundance is highly sensitive to the primordial curvature power spectrum because the PBH formation fraction depends exponentially on density fluctuations. Although an early PBH-dominated era dilutes pre-existing abundances and reduces the apparent tuning of the PBH abundance, inflationary fine-tuning remains required to produce the required initial large amplitude perturbations. We further examine alternative PBH formation channels, including supercooled first-order phase transitions and collapsing domain walls, and find that they replace the inflationary fine-tuning with alternative exponential sensitivities. We conclude that a natural realization of an order unity PBH relic abundance is hard to motivate.

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Reference graph

Works this paper leans on

82 extracted references · 13 canonical work pages

  1. [33]

    Comprehensively Constraining Ultra-Light Primordial Black Holes Through Relic Formation and Early Mergers

    Amirah Aljazaeri and Christian T. Byrnes. “Comprehensively constraining ultra-light primor- dial black holes through relic formation and early mergers”. In: JCAP 10 (2025), p. 083.doi: 10.1088/1475-7516/2025/10/083. arXiv:2506.16154 [astro-ph.CO]

  2. [1]

    Rotational properties of 21 SC galaxies with a large range of luminosities and radii, from NGC 4605 (R=4kpc) to UGC 2885 (R=122kpc)

    Vera C Rubin, W Kent Ford Jr, and Norbert Thonnard. “Rotational properties of 21 SC galaxies with a large range of luminosities and radii, from NGC 4605 (R=4kpc) to UGC 2885 (R=122kpc).” In: The Astrophysical Journal 238 (1980), pp. 471–487.doi:10.1086/158003

  3. [2]

    Rotation of the Andromeda Nebula from a Spectroscopic Survey of Emission Regions

    Vera C Rubin and W Kent Ford Jr. “Rotation of the Andromeda Nebula from a Spectroscopic Survey of Emission Regions”. In: The Astrophysical Journal 159 (1970), pp. 379–403.doi:10. 1086/150317

  4. [3]

    A Direct Empirical Proof of the Existence of Dark Matter

    Douglas Clowe et al. “A Direct Empirical Proof of the Existence of Dark Matter”. In: The Astrophysical Journal Letters 648.2 (2006), pp. L109–L113.doi:10.1086/508162

  5. [4]

    Planck 2018 results. VI. Cosmological parameters

    Planck Collaboration. “Planck 2018 results. VI. Cosmological parameters”. In: Astronomy & Astrophysics 641 (2020), A6.doi:10 . 1051 / 0004 - 6361 / 201833910. arXiv: 1807.06209

  6. [5]

    The Evolution of Large-Scale Structure in a Universe Dominated by Cold Dark Matter

    Marc Davis et al. “The Evolution of Large-Scale Structure in a Universe Dominated by Cold Dark Matter”. In: The Astrophysical Journal 292 (1985), pp. 371–394.doi:10.1086/163168

  7. [6]

    Simulations of the formation, evolution and clustering of galaxies and quasars

    Volker Springel et al. “Simulations of the formation, evolution and clustering of galaxies and quasars”. In: Nature 435.7042 (2005), pp. 629–636.doi:10.1038/nature03597. arXiv:astro- ph/0504097

  8. [7]

    Particle Dark Matter: Evidence, Candidates and Constraints

    Gianfranco Bertone, Dan Hooper, and Joseph Silk. “Particle Dark Matter: Evidence, Candidates and Constraints”. In: Physics Reports 405.5–6 (2005), pp. 279–390.doi:10.1016/j.physrep. 2004.08.031. arXiv:hep-ph/0404175

Show all 82 references
  1. [8]

    History of Dark Matter

    Gianfranco Bertone and Dan Hooper. “History of Dark Matter”. In: Reviews of Modern Physics 90.4 (2018), p. 045002.doi:10.1103/RevModPhys.90.045002. arXiv:1605.04909

  2. [9]

    Constraint on the Photino Mass from Cosmology

    Howard Goldberg. “Constraint on the Photino Mass from Cosmology”. In: Physical Review Letters 50.19 (1983), pp. 1419–1422.doi:10.1103/PhysRevLett.50.1419

  3. [10]

    Supersymmetric Relics from the Big Bang

    John Ellis et al. “Supersymmetric Relics from the Big Bang”. In: Nuclear Physics B 238.2 (1984), pp. 453–476.doi:10.1016/0550-3213(84)90461-9

  4. [11]

    Supersymmetric Dark Matter

    Gerard Jungman, Marc Kamionkowski, and Kim Griest. “Supersymmetric Dark Matter”. In: Physics Reports 267.5–6 (1996), pp. 195–373.doi:10.1016/0370- 1573(95)00058- 5. arXiv: hep-ph/9506380

  5. [12]

    Dark Matter Search Results from a One Ton-Year Exposure of XENON1T

    Elena Aprile et al. “Dark Matter Search Results from a One Ton-Year Exposure of XENON1T”. In: Physical Review Letters 121.11 (2018), p. 111302.doi:10.1103/PhysRevLett.121.111302. arXiv:1805.12562

  6. [13]

    First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experi- ment

    Jelle Aalbers et al. “First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experi- ment”. In: Physical Review Letters 131.4 (2023), p. 041002.doi:10.1103/PhysRevLett.131. 041002. arXiv:2207.03764

  7. [14]

    Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data

    M Ackermann et al. “Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data”. In: Physical Review Letters 115.23 (2015), p. 231301.doi:10.1103/PhysRevLett.115.231301. arXiv:1503.02641

  8. [15]

    Multicomponent Dark Matter in Supersymmetric Hidden Sector Ex- tensions

    Daniel Feldman et al. “Multicomponent Dark Matter in Supersymmetric Hidden Sector Ex- tensions”. In: Physical Review D 81.9 (2010), p. 095017.doi:10.1103/PhysRevD.81.095017. arXiv:1004.0649

  9. [16]

    Multi-component Dark Matter

    Chao-Qiang Geng, Da Huang, and Chang Lai. “Multi-component Dark Matter”. In: International Journal of Modern Physics A 30.28–29 (2015), p. 1545009.doi:10 . 1142 / S0217751X15450098. arXiv:1510.04476. – 21 –

  10. [17]

    Thermally Generated Gauge Singlet Scalars as Self-Interacting Dark Matter

    John McDonald. “Thermally Generated Gauge Singlet Scalars as Self-Interacting Dark Matter”. In: Physical Review Letters 88.9 (2002), p. 091304.doi:10.1103/PhysRevLett.88.091304. arXiv:hep-ph/0106249

  11. [18]

    Freeze-In Production of FIMP Dark Matter

    Lawrence J. Hall et al. “Freeze-In Production of FIMP Dark Matter”. In: Journal of High Energy Physics 2010.80 (2010), pp. 1–33.doi:10 . 1007 / JHEP03(2010 ) 080. arXiv:0911.1120

  12. [19]

    The hypothesis of cores retarded during expansion and the hot cosmological model

    Ya B Zel’dovich and ID Novikov. “The hypothesis of cores retarded during expansion and the hot cosmological model”. In: Astronomicheskii Zhurnal 43 (1966), p. 758

  13. [20]

    Gravitationally collapsed objects of very low mass

    Stephen Hawking. “Gravitationally collapsed objects of very low mass”. In: Monthly Notices of the Royal Astronomical Society 152.1 (1971), pp. 75–78.doi:10 . 1093/mnras/152.1.75

  14. [21]

    Black holes in the early Universe

    Bernard J Carr and Stephen W Hawking. “Black holes in the early Universe”. In: Monthly Notices of the Royal Astronomical Society 168.2 (1974), pp. 399–415.doi:10.1093/ mnras/168.2.399

  15. [22]

    Cosmological effects of primordial black holes

    George F Chapline. “Cosmological effects of primordial black holes”. In: Nature 253.5489 (1975), pp. 251–252.doi:10.1038/253251a0

  16. [23]

    Constraints on primordial black holes

    Bernard Carr et al. “Constraints on primordial black holes”. In: Reports on Progress in Physics 84.11 (2021), p. 116902. arXiv:2002.12778

  17. [24]

    Primordial black holes—perspectives in gravitational wave astronomy

    Misao Sasaki et al. “Primordial black holes—perspectives in gravitational wave astronomy”. In: Classical and Quantum Gravity 35.6 (2018), p. 063001. arXiv:1801.05235

  18. [25]

    Primordial black holes, a small review

    Alexandre Arbey. “Primordial black holes, a small review”. In: arXiv preprint (2024). arXiv: 2405.08624 [astro-ph.CO]

  19. [26]

    Primordial black holes: constraints, potential evidence and prospects

    Bernard Carr et al. “Primordial black holes: constraints, potential evidence and prospects”. In: La Rivista del Nuovo Cimento 49 (2026), pp. 225–274.doi:10.1007/s40766-026-00080-z

  20. [27]

    Particle creation by black holes

    Stephen W Hawking. “Particle creation by black holes”. In: Communications in mathematical physics 43.3 (1975), pp. 199–220.doi:10.1007/BF02345020

  21. [28]

    Particle Emission Rates from a Black Hole. II. Massless Particles from a Rotating Hole

    Don N. Page. “Particle Emission Rates from a Black Hole. II. Massless Particles from a Rotating Hole”. In: Physical Review D 14.12 (1976), pp. 3260–3273.doi:10.1103/PhysRevD.14.3260

  22. [29]

    Dark radiation and superheavy dark matter from black hole domination

    Dan Hooper, Gordan Krnjaic, and Samuel D McDermott. “Dark radiation and superheavy dark matter from black hole domination”. In: Journal of High Energy Physics 2019.8 (2019), pp. 1–

  23. [30]

    Black hole relics and inflation: Limits on blue perturbation spectra

    B. J. Carr, J. H. Gilbert, and James E. Lidsey. “Black hole relics and inflation: Limits on blue perturbation spectra”. In: Physical Review D 50.8 (Oct. 1994), pp. 4853–4867.issn: 0556-2821. arXiv:astro-ph/9405027

  24. [31]

    Inflation induced Planck-size black hole remnants as dark matter

    Pisin Chen. “Inflation induced Planck-size black hole remnants as dark matter”. In: New Astronomy Reviews 49.2–6 (May 2005), pp. 233–239.issn: 1387-6473. arXiv:astro - ph/0406514

  25. [32]

    Constraints on the density perturbation spectrum from primordial black holes

    Anne M. Green and Andrew R. Liddle. “Constraints on the density perturbation spectrum from primordial black holes”. In: Physical Review D 56.10 (Nov. 1997), pp. 6166–6174.issn: 1089-4918. arXiv:astro-ph/9704251

  26. [34]

    Primordial Black Holes as Dark Matter: Almost All or Almost Nothing

    Brian C. Lacki and John F. Beacom. “Primordial Black Holes as Dark Matter: Almost All or Almost Nothing”. In: Astrophys. J. Lett. 720 (2010), pp. L67–L71.doi:10 . 1088 / 2041 - 8205/720/1/L67. arXiv:1003.3466 [astro-ph.CO]. – 22 –

  27. [35]

    WIMPs and stellar-mass primordial black holes are incompatible

    Julian Adamek et al. “WIMPs and stellar-mass primordial black holes are incompatible”. In: Phys. Rev. D 100.2 (2019), p. 023506.doi:10.1103/PhysRevD.100.023506. arXiv:1901.08528 [astro-ph.CO]

  28. [36]

    Black holes and WIMPs: all or nothing or something else

    Bernard Carr, Florian Kuhnel, and Luca Visinelli. “Black holes and WIMPs: all or nothing or something else”. In: Mon. Not. Roy. Astron. Soc. 506.3 (2021), pp. 3648–3661.doi:10.1093/ mnras/stab1930. arXiv:2011.01930 [astro-ph.CO]

  29. [37]

    Evolution of the DM distribution function in the density spikes around PBHs

    Yu. N. Eroshenko. “Evolution of the DM distribution function in the density spikes around PBHs”. In: Journal of Cosmology and Astroparticle Physics 2024.08 (2024), p. 019.doi:10. 1088/1475-7516/2024/08/019. arXiv:2407.10225

  30. [38]

    In-depth analysis of the clustering of dark matter particles around primordial black holes. Part III. CMB constraints

    Julien Lavalle, Vivian Poulin, and Pierre Salati. “In-depth analysis of the clustering of dark matter particles around primordial black holes. Part III. CMB constraints”. In:JCAP 06 (2026), p. 092.doi:10.1088/1475-7516/2026/06/092. arXiv:2604.18007 [astro-ph.CO]

  31. [39]

    The Dawn of FIMP Dark Matter: A Review of Models and Constraints

    Nicol´ as Bernal et al. “The Dawn of FIMP Dark Matter: A Review of Models and Constraints”. In: Int. J. Mod. Phys. A 32.27 (2017), p. 1730023.doi:10.1142/S0217751X1730023X. arXiv: 1706.07442 [hep-ph]

  32. [40]

    CP Conservation in the Presence of Instantons

    Roberto D Peccei and Helen R Quinn. “CP Conservation in the Presence of Instantons”. In: Physical Review Letters 38.25 (1977), pp. 1440–1443.doi:10.1103/PhysRevLett.38.1440

  33. [41]

    Problem of Strong P and T Invariance in the Presence of Instantons

    Frank Wilczek. “Problem of Strong P and T Invariance in the Presence of Instantons”. In: Physical Review Letters 40.5 (1978), pp. 279–282.doi:10.1103/PhysRevLett.40.279

  34. [42]

    Cosmology of the Invisible Axion

    John Preskill, Mark B. Wise, and Frank Wilczek. “Cosmology of the Invisible Axion”. In: Physics Letters B 120.1–3 (1983), pp. 127–132.doi:10.1016/0370-2693(83)90637-8

  35. [43]

    A Cosmological Bound on the Invisible Axion

    Laurence F Abbott and Pierre Sikivie. “A Cosmological Bound on the Invisible Axion”. In: Physical Review Letters 50.19 (1983), pp. 1410–1413.doi:10.1103/PhysRevLett.50.1410

  36. [44]

    Axion Cosmology

    David J. E. Marsh. “Axion Cosmology”. In: Physics Reports 643 (2016), pp. 1–79.doi:10. 1016/j.physrep.2016.06.005. arXiv:1510.07633

  37. [45]

    Upper Bounds on Supersymmetric Particle Masses

    Riccardo Barbieri and Gian Francesco Giudice. “Upper Bounds on Supersymmetric Particle Masses”. In: Nuclear Physics B 306.1 (1988), pp. 63–76.doi:10.1016/0550-3213(88)90171- X

  38. [46]

    Observables in Low-Energy Superstring Models

    John Ellis et al. “Observables in Low-Energy Superstring Models”. In: Modern Physics Letters A 1.1 (1986), pp. 57–69.doi:10.1142/S0217732386000105

  39. [47]

    The Primordial Black Hole Mass Spectrum

    Bernard J. Carr. “The Primordial Black Hole Mass Spectrum”. In: The Astrophysical Journal 201 (1975), pp. 1–19.doi:10.1086/153853

  40. [48]

    Steepest Growth of the Power Spectrum and Primordial Black Holes

    Christian T. Byrnes, Philippa S. Cole, and Subodh P. Patil. “Steepest Growth of the Power Spectrum and Primordial Black Holes”. In: Journal of Cosmology and Astroparticle Physics 2019.06 (2019), p. 028.doi:10.1088/1475-7516/2019/06/028. arXiv:1811.11158

  41. [49]

    Primordial black holes from single-field inflation: a fine-tuning audit

    Philippa S. Cole et al. “Primordial black holes from single-field inflation: a fine-tuning audit”. In: Journal of Cosmology and Astroparticle Physics 2023.08 (2023), p. 031.doi:10.1088/1475- 7516/2023/08/031. arXiv:2304.01997

  42. [50]

    Production of Primordial Black Holes in Improved E- Models of Inflation

    Daniel Frolovsky and Sergei V. Ketov. “Production of Primordial Black Holes in Improved E- Models of Inflation”. In: Universe 9.6 (2023), p. 294.doi:10.3390/universe9060294. arXiv: 2304.12558 [astro-ph.CO]

  43. [51]

    Mechanisms for Producing Primordial Black Holes from Inflationary Models beyond Fine-Tuning

    Ioanna Stamou. “Mechanisms for Producing Primordial Black Holes from Inflationary Models beyond Fine-Tuning”. In: Universe 10.6 (2024), p. 241.doi:10 . 3390 / universe10060241. arXiv:2404.14321 [astro-ph.CO]

  44. [52]

    Primordial Black Holes from Inflation with a Spectator Field

    Dario L. Lorenzoni et al. “Primordial Black Holes from Inflation with a Spectator Field”. In: arXiv preprint (Dec. 2025). arXiv:2512.04199 [astro-ph.CO]. – 23 –

  45. [53]

    Are primordial black holes truly fine-tuned?

    A. J. Iovino and A. Riotto. “Are primordial black holes truly fine-tuned?” In: JCAP 07 (2026), p. 047.doi:10.1088/1475-7516/2026/07/047. arXiv:2512.19668 [astro-ph.CO]

  46. [54]

    Are Primordial Black Holes a Natural Dark Matter Candidate?

    Stefano Profumo. “Are Primordial Black Holes a Natural Dark Matter Candidate?” In: arXiv preprint (2026). arXiv:2606.12775

  47. [55]

    Tensor-Induced Backreaction in Ultra-Slow-Roll Inflation

    Alessandro Ciaiolo and Giovanni Marozzi. “Tensor-Induced Backreaction in Ultra-Slow-Roll Inflation”. In: (Aug. 2026). arXiv:2608.07264 [astro-ph.CO]

  48. [56]

    Can Planck-mass relics of evaporating black holes close the Universe?

    Jane H MacGibbon. “Can Planck-mass relics of evaporating black holes close the Universe?” In: Nature 329.6137 (1987), pp. 308–309.doi:10.1038/329308a0

  49. [57]

    Black hole genesis of dark matter

    Olivier Lennon et al. “Black hole genesis of dark matter”. In: Journal of Cosmology and Astroparticle Physics 2018.04 (2018), p. 009. arXiv:1712.07664

  50. [58]

    Science with the space-based interferometer eLISA. II: Gravitational waves from cosmological phase transitions

    Chiara Caprini et al. “Science with the space-based interferometer eLISA. II: Gravitational waves from cosmological phase transitions”. In: Journal of Cosmology and Astroparticle Physics 2016.04 (2016), p. 001.doi:10.1088/1475- 7516/2016/04/001. arXiv:1512.06239

  51. [59]

    Primordial Black Holes from Supercooled Phase Tran- sitions

    Yann Gouttenoire and Tomer Volansky. “Primordial Black Holes from Supercooled Phase Tran- sitions”. In: Physical Review D 110.4 (2024), p. 043514.doi:10.1103/PhysRevD.110.043514. arXiv:2305.04942

  52. [60]

    Primordial Black Holes and Wormholes from Domain Wall Networks

    Yann Gouttenoire and Edoardo Vitagliano. “Primordial Black Holes and Wormholes from Domain Wall Networks”. In: Physical Review D 109.12 (2024), p. 123507.doi:10 . 1103 / PhysRevD.109.123507. arXiv:2311.07670

  53. [61]

    Domain wall interpretation of the PTA signal confronting black hole overproduction

    Yann Gouttenoire and Edoardo Vitagliano. “Domain wall interpretation of the PTA signal confronting black hole overproduction”. In: Physical Review D 110.6 (2024), p. L061306.doi: 10.1103/PhysRevD.110.L061306. arXiv:2306.17841

  54. [62]

    Primordial Black Hole Baryogenesis

    Daniel Baumann, Paul J. Steinhardt, and Neil Turok. “Primordial Black Hole Baryogenesis”. In: arXiv preprint (2007). arXiv:hep-th/0703250

  55. [63]

    Melanopogenesis: Dark Matter of (almost) any Mass and Baryonic Matter from the Evaporation of Primordial Black Holes weighing a Ton (or less)

    Logan Morrison, Stefano Profumo, and Yan Yu. “Melanopogenesis: Dark Matter of (almost) any Mass and Baryonic Matter from the Evaporation of Primordial Black Holes weighing a Ton (or less)”. In: Journal of Cosmology and Astroparticle Physics 2019.05 (2019), p. 005. arXiv: 1812.10606

  56. [64]

    Dark Matter in the Time of Primordial Black Holes

    Nicol´ as Bernal and ´Oscar Zapata. “Dark Matter in the Time of Primordial Black Holes”. In: Journal of Cosmology and Astroparticle Physics 2021.03 (2021), p. 015.doi:10.1088/1475- 7516/2021/03/015. arXiv:2011.12306

  57. [65]

    The Atacama Cosmology Telescope: DR6 Constraints on Extended Cosmological Models

    Erminia Calabrese et al. “The Atacama Cosmology Telescope: DR6 Constraints on Extended Cosmological Models”. In: JCAP 11 (2025), p. 063.doi:10.1088/1475-7516/2025/11/063. arXiv:2503.14454 [astro-ph.CO]

  58. [66]

    Primordial black hole evaporation and dark matter production. II. Inter- play with the freeze-in or freeze-out mechanism

    Andrew Cheek et al. “Primordial black hole evaporation and dark matter production. II. Inter- play with the freeze-in or freeze-out mechanism”. In:Physical Review D 105.1 (2022), p. 015023. doi:10.1103/PhysRevD.105.015023. arXiv:2107.00016

  59. [67]

    WIMPs during Reheating

    Nicol´ as Bernal and Yong Xu. “WIMPs during Reheating”. In: Journal of Cosmology and Astroparticle Physics 2022.12 (2022), p. 017.doi:10.1088/1475- 7516/2022/12/017. arXiv:2209.07546

  60. [68]

    What Naturalness Measures: Fine-Tuning and Informational Invariants in Cosmology and Dark Matter

    Stefano Profumo. “What Naturalness Measures: Fine-Tuning and Informational Invariants in Cosmology and Dark Matter”. In: (June 2026). arXiv:2606.29660 [physics.hist-ph]

  61. [69]

    Formation of Galaxies and Clusters of Galaxies by Self- Similar Gravitational Condensation

    William H. Press and Paul Schechter. “Formation of Galaxies and Clusters of Galaxies by Self- Similar Gravitational Condensation”. In: Astrophys. J. 187 (1974), pp. 425–438.doi:10.1086/ 152650. – 24 –

  62. [70]

    Computations of primordial black hole formation

    Ilia Musco, John C. Miller, and Luciano Rezzolla. “Computations of primordial black hole formation”. In: Classical and Quantum Gravity 22.7 (2005), pp. 1405–1424.doi:10 . 1088 / 0264-9381/22/7/013. arXiv:gr-qc/0412063

  63. [71]

    A New Light Boson?

    Steven Weinberg. “A New Light Boson?” In: Physical Review Letters 40.4 (1978), pp. 223–226. doi:10.1103/PhysRevLett.40.223

  64. [72]

    The Landscape of QCD Axion Models

    Luca Di Luzio et al. “The Landscape of QCD Axion Models”. In: Physics Reports 870 (2020), pp. 1–117.doi:10.1016/j.physrep.2020.06.002. arXiv:2003.01100

  65. [73]

    Relic Density of Axion Dark Matter in Standard and Non- Standard Cosmological Scenarios

    Moira Andrea Venegas Villa. “Relic Density of Axion Dark Matter in Standard and Non- Standard Cosmological Scenarios”. In: arXiv preprint (2021). arXiv:2106.07796 [hep-ph]

  66. [74]

    Bubble Collisions in the Very Early Universe

    Stephen W. Hawking, Ian G. Moss, and John M. Stewart. “Bubble Collisions in the Very Early Universe”. In: Physical Review D 26.10 (1982), pp. 2681–2693.doi:10.1103/PhysRevD.26. 2681

  67. [75]

    Abundance of Primordial Holes Produced by Cosmological First-Order Phase Transition

    Hideo Kodama, Misao Sasaki, and Katsuhiko Sato. “Abundance of Primordial Holes Produced by Cosmological First-Order Phase Transition”. In:Progress of Theoretical Physics 68.6 (1982), pp. 1979–1998.doi:10.1143/PTP.68.1979

  68. [76]

    Primordial Black Holes from Bubble Collisions during a First-Order Phase Transition

    Tae Hyun Jung and Takemichi Okui. “Primordial Black Holes from Bubble Collisions during a First-Order Phase Transition”. In: Physical Review D 110.11 (2024), p. 115014.doi:10.1103/ PhysRevD.110.115014. arXiv:2110.04271

  69. [77]

    Gravitational Waves and Black Holes from the Phase Transition in Models of Dynamical Symmetry Breaking

    Mart ´ ın Arteaga, Anish Ghoshal, and Alessandro Strumia. “Gravitational Waves and Black Holes from the Phase Transition in Models of Dynamical Symmetry Breaking”. In: Journal of Cosmology and Astroparticle Physics 2025.05 (2025), p. 029.doi:10.1088/1475- 7516/2025/05/029. arX...

  70. [78]

    Curvature Perturbations from First-Order Phase Transitions: Implications to Black Holes and Gravitational Waves

    Gabriele Franciolini, Yann Gouttenoire, and Ryusuke Jinno. “Curvature Perturbations from First-Order Phase Transitions: Implications to Black Holes and Gravitational Waves”. In: Physical Review Letters 136.17 (2026), p. 171404.doi:10.1103/PhysRevLett.136.171404. arXiv:2503.01962

  71. [79]

    Reviving Primordial Black Hole Formation in Slow First-Order Phase Transitions

    Wen-Yuan Ai and Ke-Pan Xie. “Reviving Primordial Black Hole Formation in Slow First-Order Phase Transitions”. In: arXiv preprint (2026). arXiv:2605.11332

  72. [80]

    Can the universe be matter- dominated after a supercooled first-order phase transition?

    Henda Mansour, Yann Gouttenoire, and Felix Kahlhoefer. “Can the universe be matter- dominated after a supercooled first-order phase transition?” In: arXiv preprint (July 2026). arXiv:2607.19469 [hep-ph]

  73. [81]

    Cosmological Consequences of Domain Walls Biased by Quantum Gravity

    Yann Gouttenoire et al. “Cosmological Consequences of Domain Walls Biased by Quantum Gravity”. In: Physical Review D 112.7 (2025), p. 075007.doi:10.1103/PhysRevD.112.075007. arXiv:2501.16414

  74. [82]

    Black Hole Metamorphosis and Stabilization by Memory Burden

    Gia Dvali et al. “Black Hole Metamorphosis and Stabilization by Memory Burden”. In: Physical Review D 102.10 (2020), p. 103523.doi:10 . 1103 / PhysRevD . 102 . 103523. arXiv: 2006.00011 [hep-th]. – 25 – 7 Appendex A1. Dependence on the ratio off relic andf χ In our analysis, w...

Pith tools

Reviewed August 12, 2026 · model on record in the stance chip above.