REVIEW 4 major objections 4 minor 1 cited by
A microphysically inspired approach to dark matter-dark energy interactions: first bounds on dark-sector scattering cross sections
T0 review · 4 major / 4 minor · reviewed 2026-08-03 · deepseek-v4-flash
Pith's one-line read The paper claims that dark matter and dark energy can exchange energy through reversible two-body collisions, and that the resulting quadratic interaction fits all background cosmological data while yielding the first tight bounds on dark-s
desk verdict A useful phenomenological constraint on a quadratic dark-sector interaction, but the advertised cross-section bounds do not follow from the model's own equations, especially for dark energy. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The load-bearing object is the interaction term Q = -A (H0/ρc,0) ρ_DM^2 + B (H0/ρc,0) ρ_DE^2, obtained from the standard Boltzmann annihilation term by substituting ρ = m n for each dark-sector species. This coarse-grained term turns the dark-matter–dark-energy coupling into a local, number-changing collision process; A and B are dimensionless coefficients that the paper reads as thermally averaged cross-sections per unit mass. Supporting the term is an effective-field-theory description with quartic operators (such as χ^2 φ^2) that realize the reversible χ+χ ↔ φ+φ channel and exclude linear decay interactions.
What would settle it
Solve the first-order perturbation equations for this Q ∝ ρ^2 interaction: if dark-energy density perturbations grow without bound on large scales in the early universe—as happens for many Hubble-proportional interacting-dark-energy models—the model is ruled out even though it fits the background data.
Extended reading notes
Core claim
The central claim is that a bottom-up interacting-dark-energy model with interaction Q = -A (H0/ρc,0) ρ_DM^2 + B (H0/ρc,0) ρ_DE^2 is viable. The quadratic form follows from the Boltzmann collision term for a 2-to-2 process χ+χ ↔ φ+φ after writing number densities as mass densities. Using supernova distances, cosmic chronometers, baryon acoustic oscillations, and CMB distance priors, the model fits the data as well as flat ΛCDM, with H0 = 67.71 ± 0.65 km/s/Mpc and 95% upper limits A < 7.586 × 10^-25 and B < 0.048. The paper's key interpretive step is that these dimensionless coefficients, together with the expansion rate, translate directly into limits on the thermally averaged annihilation c
Load-bearing premise
The cross-section interpretation rests on treating dark energy as a gas of non-relativistic particles with a definite mass, so that its energy density equals mass times number density; if dark energy is a cosmological constant or a field whose energy cannot be counted as particles, the B term and its bound lose their microphysical meaning.
Editorial extensions
If this is right
- Dark-matter self-annihilation into dark-energy states is forced to be extremely weak, with A below 7.6 × 10^-25, making such a process cosmologically negligible.
- The dark-energy-side coupling is only bounded at B < 0.048, so the reverse process could still be active at the few-percent level.
- The model prefers H0 ≈ 67.7 km/s/Mpc, aligning with early-universe estimates rather than the higher local values, so it does not resolve the Hubble tension by raising H0.
- The interaction coefficients are strongly correlated with the sound horizon; CMB distance priors fix the sound horizon near 147.7 Mpc and thereby suppress the allowed interaction range.
- The model's fit quality is nearly identical to flat ΛCDM, so any detectable signature must come from epochs or observables where the quadratic interaction term is larger, not from the late-time background expansion alone.
Reading between the lines
- Editorial extension: if the interaction really is quadratic in densities, its effects scale strongly with redshift, so nucleosynthesis or recombination-era data may provide much stronger tests than the late-time background probes used here.
- Editorial extension: the B-bound's lack of a particle interpretation is a genuine open question—if dark energy is a bare cosmological constant, the central cross-section claim reduces to a constraint on an effective coefficient, not a physical scattering rate.
- Editorial extension: the same Boltzmann-derived interaction could be applied to dark matter–dark radiation or dark matter–dark matter self-interactions in the early universe, where the resulting relic-density changes would be observable.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proposes an interacting dark energy–dark matter model with interaction term Q = -A (H0/ρc,0) ρ_DM^2 + B (H0/ρc,0) ρ_DE^2, motivated by a Boltzmann collision term for the reversible process χχ ↔ φφ. The model is fit to Pantheon+, cosmic chronometers, DESI DR2 BAO, and Planck distance priors. The combined analysis yields H0 = 67.71 ± 0.65 km/s/Mpc and 95% upper limits A < 7.586×10^-25 and B < 0.048. The authors claim these limits translate into bounds on thermally-averaged annihilation cross-sections per unit mass, and that the model fits the data comparably to flat ΛCDM.
Significance. If the microphysical mapping were sound, this would be a useful step toward particle-physics-motivated interacting dark energy models, avoiding the H-dependent interaction terms that suffer from large-scale instabilities. The dataset combination is current and the paper is transparent about many numerical details, including the bimodality of the B posterior and per-dataset chi-square values. However, the central cross-section interpretation is not established: the Boltzmann-to-fluid mapping fails for a w ≈ -1 dark energy field, the forward and reverse rates are not independent, and no numerical cross-section limit is actually computed. The results are plausible as phenomenological background constraints on a ρ² interaction, but the advertised claim of 'first bounds on dark-sector scattering cross sections' overreaches.
major comments (4)
- [Section II–III, Eqs. (4)–(6)] Equation (6) is not a valid two-species reduction of the Boltzmann equation. Equation (5) uses ρ = m n, which is appropriate only for non-relativistic, dilute particles. Section III explicitly models dark energy as a light scalar field or condensate with w ≈ -1; for such a field the energy density is potential-dominated and there is no conserved particle number, so n_DE and m_DE entering Eq. (5) are undefined. The B term therefore has no particle-scattering interpretation, and the claimed dark-energy annihilation cross-section bound is unsupported. In addition, for a single χχ ↔ φφ process, forward and reverse rates are related by detailed balance; treating A and B as independent positive coefficients requires a microphysical justification that the paper does not provide.
- [Title, Abstract, Section V, Conclusion] No cross-section bound is ever presented. The title and abstract advertise a limit on the thermally-averaged annihilation cross-section per unit mass, but the paper only reports constraints on the dimensionless coefficients A and B. If Eqs. (5)–(6) are accepted, the conversion is ⟨σv⟩/m_χ = A H0/ρc,0, yet no numerical value with units is given anywhere. The authors should either state the derived cross-section limits explicitly with units and error propagation, or revise the central claim to be purely a bound on the coefficients A and B.
- [Appendix A, Figures 2–3] The posterior for B is bimodal, with a best-fit peak at the edge of the sampled range. The paper itself describes a 'sharp tip at the end of the sample' and shows a two-peaked likelihood distribution. A 95% upper limit B < 0.048 obtained from such a posterior is not a stable summary statistic and is not robust evidence of a constraint. A profile-likelihood analysis or a prior-sensitivity check is needed before B can be quoted as a headline upper limit.
- [Section V and Appendix A, Table III] The reported reduced chi-square for the full combination is inconsistent: the main text states χ²ν = 0.8889, while Table III gives 0.8805. One of these values is wrong. Additionally, Table III shows that the IDE model fits BAO alone and BAO+PCMB substantially worse than ΛCDM (χ²ν = 1.5050 vs 1.1426 and 1.7362 vs 1.3379, respectively). This is acknowledged only in passing, yet it weakens the conclusion that the model 'fits the observational data with high precision.' The BAO tension should be quantified and discussed in the context of the combined fit.
minor comments (4)
- [Section V] The text says 'log10 A < 7.586×10^-25', which is dimensionally inconsistent. It should read A < 7.586×10^-25, or equivalently log10 A < -24.12.
- [Table II] The header 'Top 5% Max' is unclear; the standard definition of the 95% upper limit should be stated explicitly.
- [Figures 2–3] The vertical axis is labeled 'Log Probability (ln)' but the text refers to lnL (log-likelihood); the labeling should be made consistent and precise.
- [Eq. (6)] The normalization by H0/ρc,0 is arbitrary from a microphysical viewpoint. The authors should state clearly that A and B are defined relative to this cosmological normalization, and that this choice affects the numerical values of the quoted bounds.
Circularity Check
The headline cross-section bounds are the fitted A/B couplings rescaled by constants, not independent predictions.
-
fitted input called prediction
[Section II, Eqs. (5)-(6); Abstract and Conclusion]
"By substituting the mass density ¯ρ=mn for non-relativistic particles, the collision term in Eq. (4) takes the form: ˙¯ρψ + 3H¯ρψ = − ⟨σ|v|⟩/mψ ¯ρ^2ψ + ⟨σ|v|⟩/mψ (¯ρ^EQ_ψ)^2 (5) ... by applying Eq. (4) to dark matter and dark energy, we obtain the interaction term: Q=−A H0/¯ρc,0 ¯ρ^2_DM +B H0/¯ρc,0 ¯ρ^2_DE . (6) ... these bounds on H0, A, and B directly translate into a strict limit on the thermally-averaged annihilation cross-section per unit of mass."
Equation (6) is not derived from a separate microphysical relation; it is Eq. (5) with the identification A H0/¯ρc,0 = ⟨σ|v|⟩/mψ (and B for the dark-energy counterpart). After the MCMC fit, A and B are known, so the reported 'limit on the annihilation cross-section per unit of mass' is just the fitted dimensionless coefficient A (or B) multiplied by H0/¯ρc,0. No new datum or theory enters; the claimed first bound on the dark-sector cross-section is the fitted coupling renamed in physical units. It is a reparameterization, not a predicted quantity, and it is statistically forced by construction. The background constraints (H0, densities) are independently tested, but the title/abstract headline is this reparameterized fit. For B, the step also assumes ρ=mn for a w≈−1 scalar/condensate, whic
full rationale
No load-bearing self-citation chain was found: the Boltzmann analogy is taken from the external textbook Kolb & Turner [36], the instability discussion from Valiviita et al. [32] and He et al. [33], and the authors' own earlier papers are contextual rather than used to force the model. The model is fitted to external Pantheon+, CC, DESI DR2, and Planck distance-prior data, so the background constraints and the H0 measurement are not circular. The circular element is the central cross-section claim: Eq. (6) is constructed from Eq. (5) by identifying A and B with cross-section-per-mass parameters, so the reported cross-section limits are algebraic rescalings of the fitted A and B. That makes the advertised 'first bounds on dark-sector scattering cross sections' a fitted input called a prediction. A separate, non-circular weakness is the substitution ρ=mn for a w≈−1 scalar/condensate, which is not justified for dark energy; it further undermines the physical interpretation of the B bound but is not itself a circularity. Score 6 reflects that the central result reduces to a reparameterization while the data analysis remains externally anchored.
Assumptions & free parameters
free parameters (6)
- A (DM self-annihilation coefficient) =
< 7.586e-25 (95% CL)
- B (DE self-annihilation coefficient) =
< 0.048 (95% CL)
- H0 =
67.71 ± 0.65 km/s/Mpc
- Ω_DM0 =
0.2575 ± 0.005
- Ω_b0 =
0.04907 ± 0.00091
- w (DE equation of state) =
-0.963 ± 0.028
assumptions (5)
- standard math FLRW background equations and non-conservation of individual energy-momentum tensors (Eqs. 1-3)
- domain assumption Boltzmann collision term for number density (Eq. 4) and substitution ρ = m n (Eq. 5) apply to both DM and DE
- ad hoc to paper The interaction term Q in Eq. (6) is the correct coarse-grained form of χ+χ ↔ φ+φ
- domain assumption Dark energy is a dynamical field, not a cosmological constant
- domain assumption CMB distance priors and DESI DR2 BAO measurements are accurate
invented entities (2)
-
Effective field theory operator L_int ∝ χ²φ² (and vector/Majorana variants)
-
Dark energy field φ as a light scalar/condensate with particle-like excitations
Cite this review
Pith. "Pith review of A microphysically inspired approach to dark matter-dark energy interactions: first bounds on dark-sector scattering cross sections." pith.science (2026). https://pith.science/paper/F54HOCWA
@misc{pith2026260105646,
author = {Pith},
title = {Pith review of: A microphysically inspired approach to dark matter-dark energy interactions: first bounds on dark-sector scattering cross sections},
year = {2026},
howpublished = {\url{https://pith.science/paper/F54HOCWA}},
note = {Machine review of arXiv:2601.05646}
}
abstract
The observational tension regarding the value of the Hubble constant ($H_0$) has motivated the exploration of alternative cosmological scenarios, including Interacting Dark Energy models. However, the majority of IDE models studied in the literature rely on phenomenological interaction terms proportional to the Hubble parameter (e.g., $Q\propto H\rho$), which lack a clear microphysical justification and often suffer from large-scale instabilities. In this work, we propose and investigate a "bottom-up" IDE model where the interaction is formulated directly from particle physics collision processes, taking the form $Q\propto\rho^2$. This interaction represents a reversible annihilation/creation process between Dark Matter and Dark Energy, motivated by the Boltzmann equation. We test this model against a combination of background cosmological data, Pantheon Plus, Cosmic Chronometers, DESI DR2, and CMB distance priors from Planck18. We find that the model is consistent with the data, yielding a Hubble constant of $H_0=67.71\pm0.65$ km s$^{-1}$ Mpc$^{-1}$ for the combined analysis. The dimensionless interaction rate coefficients are constrained to be small, with upper limits of $A < 7.586\times10^{-25}$ (for Dark Matter self annihilation) and $B < 0.048$ (for Dark Energy self annihilation) at 95\% confidence level. Since the interaction model is parameterized by the expansion rate, these bounds on $H_0$, $A$, and $B$ directly translate into a strict limit on the thermally-averaged annihilation cross-section per unit of mass. The constraints on the coupling $A$ imply that, if such a collisional interaction exists, the effective dark-matter annihilation cross section per unit mass is highly suppressed relative to the cosmological expansion rate. In contrast, the corresponding dark-energy contribution, governed by $B$, is only constrained at the level of a few percent in dimensionless units.
Figures
Forward citations
Cited by 1 Pith paper
-
Unifying Early and Late Dark Energy: Dynamical Requirements and Obstructions
Any unified early and late dark energy scenario with a single tracking scalar field requires a potential with three distinct slopes arranged in a steep-steeper-shallow hierarchy.
Reference graph
Works this paper leans on
-
[1]
R. L. Workmanet al.(Particle Data Group), Review of Particle Physics, PTEP2022, 083C01 (2022)
2022
-
[2]
Aghanimet al.(Planck), Planck 2018 results
N. Aghanimet al.(Planck), Planck 2018 results. VI. Cosmological parameters, Astron. Astrophys.641, A6 (2020), [Erratum: Astron.Astrophys. 652, C4 (2021)], arXiv:1807.06209 [astro-ph.CO]
arXiv 2018
-
[3]
Broutet al., The Pantheon+ Analysis: Cosmo- logical Constraints, Astrophys
D. Broutet al., The Pantheon+ Analysis: Cosmo- logical Constraints, Astrophys. J.938, 110 (2022), arXiv:2202.04077 [astro-ph.CO]
arXiv 2022
-
[4]
Morescoet al., Unveiling the Universe with emerg- ing cosmological probes, Living Rev
M. Morescoet al., Unveiling the Universe with emerg- ing cosmological probes, Living Rev. Rel.25, 6 (2022), arXiv:2201.07241 [astro-ph.CO]
arXiv 2022
-
[5]
E. Abdallaet al., Cosmology intertwined: A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies, JHEAp 34, 49 (2022), arXiv:2203.06142 [astro-ph.CO]
arXiv 2022
-
[6]
L. Perivolaropoulos and F. Skara, Challenges for ΛCDM: An update, New Astron. Rev.95, 101659 (2022), arXiv:2105.05208 [astro-ph.CO]
arXiv 2022
-
[7]
L. S. Brito, J. F. Jesus, A. A. Escobal, and S. H. Pereira, Can decaying vacuum solve theH 0 tension?, Eur. Phys. J. C85, 1025 (2025), arXiv:2412.06756 [astro-ph.CO]
arXiv 2025
-
[8]
J. A. S. Lima, Alternative dark energy models: An Overview, Braz. J. Phys.34, 194 (2004), arXiv:astro- ph/0402109
arXiv 2004
Show all 44 references
-
[9]
M. B. Gavela, L. Lopez Honorez, O. Mena, and S. Rigolin, Dark Coupling and Gauge Invariance, JCAP 11, 044, arXiv:1005.0295 [astro-ph.CO]
-
[10]
G. R. Farrar and P. J. E. Peebles, Interacting dark matter and dark energy, Astrophys. J.604, 1 (2004), arXiv:astro-ph/0307316
2004 arXiv
-
[11]
von Marttens, V
R. von Marttens, V. Marra, L. Casarini, J. E. Gonzalez, and J. Alcaniz, Null test for interactions in the dark sec- tor, Phys. Rev. D99, 043521 (2019), arXiv:1812.02333 7 735 730 725 720 715 Log Probability (ln ) 100 101 102 103 104 105 Frequency Median 50 40 30 20 10 0 log10 ...
2019 arXiv
-
[12]
Salvatelli, N
V. Salvatelli, N. Said, M. Bruni, A. Melchiorri, and D. Wands, Indications of a late-time interaction in the dark sector, Phys. Rev. Lett.113, 181301 (2014), arXiv:1406.7297 [astro-ph.CO]
2014 arXiv
-
[13]
Shafieloo, D
A. Shafieloo, D. K. Hazra, V. Sahni, and A. A. Starobin- sky, Metastable Dark Energy with Radioactive-like De- cay, Mon. Not. Roy. Astron. Soc.473, 2760 (2018), arXiv:1610.05192 [astro-ph.CO]
2018 arXiv
-
[14]
R. J. F. Marcondes, R. C. G. Landim, A. A. Costa, B. Wang, and E. Abdalla, Analytic study of the effect of dark energy-dark matter interaction on the growth of structures, JCAP12, 009, arXiv:1605.05264 [astro- ph.CO]
-
[15]
B. Wang, E. Abdalla, F. Atrio-Barandela, and D. Pavon, Dark Matter and Dark Energy Interactions: Theoreti- cal Challenges, Cosmological Implications and Observa- tional Signatures, Rept. Prog. Phys.79, 096901 (2016), arXiv:1603.08299 [astro-ph.CO]
2016 arXiv
-
[16]
R. F. vom Marttens, L. Casarini, W. S. Hip´ olito- Ricaldi, and W. Zimdahl, CMB and matter power spectra with non-linear dark-sector interactions, JCAP01, 050, arXiv:1610.01665 [astro-ph.CO]
-
[17]
Santos, W
L. Santos, W. Zhao, E. G. M. Ferreira, and J. Quintin, Constraining interacting dark energy with CMB and BAO future surveys, Phys. Rev. D96, 103529 (2017), arXiv:1707.06827 [astro-ph.CO]
2017 arXiv
-
[18]
W. Yang, S. Pan, and J. D. Barrow, Large-scale Sta- bility and Astronomical Constraints for Coupled Dark- Energy Models, Phys. Rev. D97, 043529 (2018), arXiv:1706.04953 [astro-ph.CO]
2018 arXiv
-
[19]
A. Cid, B. Santos, C. Pigozzo, T. Ferreira, and J. Alcaniz, Bayesian Comparison of Interacting Scenarios, JCAP03, 030, arXiv:1805.02107 [astro-ph.CO]
-
[20]
R. G. Landim, Cosmological perturbations and dynami- cal analysis for interacting quintessence, Eur. Phys. J. C 79, 889 (2019), arXiv:1908.03657 [gr-qc]
2019 arXiv
-
[21]
Di Valentino, A
E. Di Valentino, A. Melchiorri, O. Mena, and S. Vagnozzi, Interacting dark energy in the early 2020s: A promis- ing solution to theH 0 and cosmic shear tensions, Phys. Dark Univ.30, 100666 (2020), arXiv:1908.04281 [astro- ph.CO]
2020 arXiv
-
[22]
J. F. Jesus, A. A. Escobal, D. Benndorf, and S. H. Pereira, Can dark matter–dark energy interaction alle- viate the cosmic coincidence problem?, Eur. Phys. J. C 82, 273 (2022), arXiv:2012.07494 [astro-ph.CO]. 8
2022 arXiv
-
[23]
Lucca and D
M. Lucca and D. C. Hooper, Shedding light on dark matter-dark energy interactions, Phys. Rev. D102, 123502 (2020), arXiv:2002.06127 [astro-ph.CO]
2020 arXiv
-
[24]
von Marttens, J
R. von Marttens, J. E. Gonzalez, J. Alcaniz, V. Marra, and L. Casarini, Model-independent reconstruction of dark sector interactions, Phys. Rev. D104, 043515 (2021), arXiv:2011.10846 [astro-ph.CO]
2021 arXiv
-
[25]
L. A. Anchordoqui, E. Di Valentino, S. Pan, and W. Yang, Dissecting the H0 and S8 tensions with Planck + BAO + supernova type Ia in multi-parameter cos- mologies, JHEAp32, 28 (2021), arXiv:2107.13932 [astro- ph.CO]
2021 arXiv
-
[26]
Gariazzo, E
S. Gariazzo, E. Di Valentino, O. Mena, and R. C. Nunes, Late-time interacting cosmologies and the Hub- ble constant tension, Phys. Rev. D106, 023530 (2022), arXiv:2111.03152 [astro-ph.CO]
2022 arXiv
-
[27]
R. C. Nunes, S. Vagnozzi, S. Kumar, E. Di Valentino, and O. Mena, New tests of dark sector interactions from the full-shape galaxy power spectrum, Phys. Rev. D105, 123506 (2022), arXiv:2203.08093 [astro-ph.CO]
2022 arXiv
-
[28]
Bernui, E
A. Bernui, E. Di Valentino, W. Giar` e, S. Kumar, and R. C. Nunes, Exploring the H0 tension and the evidence for dark sector interactions from 2D BAO measurements, Phys. Rev. D107, 103531 (2023), arXiv:2301.06097 [astro-ph.CO]
2023 arXiv
-
[29]
Y. Zhai, W. Giar` e, C. van de Bruck, E. Di Valentino, O. Mena, and R. C. Nunes, A consistent view of inter- acting dark energy from multiple CMB probes, JCAP 07, 032, arXiv:2303.08201 [astro-ph.CO]
-
[30]
G. A. Hoerning, R. G. Landim, L. O. Ponte, R. P. Rolim, F. B. Abdalla, and E. Abdalla, Constraints on interacting dark energy revisited: Implications for the Hubble ten- sion, Phys. Rev. D112, 023523 (2025), arXiv:2308.05807 [astro-ph.CO]
2025 arXiv
-
[31]
B. Wang, E. Abdalla, F. Atrio-Barandela, and D. Pav´ on, Further understanding the interaction between dark energy and dark matter: current status and fu- ture directions, Rept. Prog. Phys.87, 036901 (2024), arXiv:2402.00819 [astro-ph.CO]
2024 arXiv
-
[32]
Valiviita, E
J. Valiviita, E. Majerotto, and R. Maartens, Instability in interacting dark energy and dark matter fluids, JCAP 07, 020, arXiv:0804.0232 [astro-ph]
-
[33]
J.-H. He, B. Wang, and E. Abdalla, Stability of the cur- vature perturbation in dark sectors’ mutual interacting models, Phys. Lett. B671, 139 (2009), arXiv:0807.3471 [gr-qc]
2009 arXiv
-
[34]
von Marttens, L
R. von Marttens, L. Casarini, D. F. Mota, and W. Zim- dahl, Cosmological constraints on parametrized interact- ing dark energy, Phys. Dark Univ.23, 100248 (2019), arXiv:1807.11380 [astro-ph.CO]
2019 arXiv
-
[35]
Figueruelo, M
D. Figueruelo, M. van der Westhuizen, A. Abebe, and E. Di Valentino, Late-time Background Constraints on Linear and Non-linear Interacting Dark Energy after DESI DR2, (2026), arXiv:2601.03122 [astro-ph.CO]
2026
-
[36]
E. W. Kolb and M. S. Turner,The Early Universe, Vol. 69 (Taylor and Francis, 2019)
2019
-
[37]
Abdul Karimet al.(DESI), DESI DR2 results
M. Abdul Karimet al.(DESI), DESI DR2 results. II. Measurements of baryon acoustic oscillations and cos- mological constraints, Phys. Rev. D112, 083515 (2025), arXiv:2503.14738 [astro-ph.CO]
2025 arXiv
-
[38]
Chen, Q.-G
L. Chen, Q.-G. Huang, and K. Wang, Distance Priors from Planck Final Release, JCAP02, 028, arXiv:1808.05724 [astro-ph.CO]
-
[39]
A. A. Escobal, J. F. Jesus, and S. H. Pereira, Cosmolog- ical constraints on scalar field dark matter, Int. J. Mod. Phys. D30, 2150108 (2021), arXiv:2004.06495 [astro- ph.CO]
2021 arXiv
-
[40]
Q. Liu, C. Feng, and F. B. Abdalla, Improved con- straints on ultralight axions using latest observations of the early and late Universe, (2025), arXiv preprint, arXiv:2511.18917 [astro-ph.CO]
2025
-
[41]
Foreman-Mackey, D
D. Foreman-Mackey, D. W. Hogg, D. Lang, and J. Good- man, emcee: The MCMC Hammer, Publ. Astron. Soc. Pac.125, 306 (2013), arXiv:1202.3665 [astro-ph.IM]
2013 arXiv
-
[42]
For the calculation of the drag epoch redshift,z d, we adopt the approximation described in [44]
LetD M be the transverse comoving distance,D H the Hubble distance,D V the isotropic BAO distance, and rs,drag the comoving sound horizon at the drag epoch. For the calculation of the drag epoch redshift,z d, we adopt the approximation described in [44]
-
[43]
Defined as:χ 2 ν ≡ χ2 min n−p [7]
-
[44]
Hu and N
W. Hu and N. Sugiyama, Small scale cosmological per- turbations: An Analytic approach, Astrophys. J.471, 542 (1996), arXiv:astro-ph/9510117
1996 arXiv
Reviewed August 3, 2026 · model on record in the stance chip above.
Discussion (0). Continue with ORCID to comment.