arxiv: 2604.11203 · v1 · submitted 2026-04-13 · ✦ hep-ph

Recognition: unknown

Bounds from D/H on baryogenesis models

Aleksandr Azatov , Bruno Missoni

Authors on Pith no claims yet

Pith reviewed 2026-05-10 15:25 UTC · model grok-4.3

classification ✦ hep-ph

keywords baryogenesisdeuterium abundanceD/H ratioelectroweak baryogenesisbaryon asymmetrybaryon inhomogeneitiescosmological constraints

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The pith

Deuterium abundance measurements leave most electroweak baryogenesis parameter space unconstrained while tightening bounds on alternative models.

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

The paper reviews limits on baryon inhomogeneities extracted from the observed deuterium-to-hydrogen ratio and applies those limits to various mechanisms proposed to explain the cosmic matter-antimatter asymmetry. It concludes that electroweak baryogenesis evades the limits over most of its relevant parameter space. Alternative baryogenesis scenarios, by contrast, encounter stronger restrictions that can remove regions previously regarded as viable. A reader would care because the result helps decide which theoretical routes to the observed baryon asymmetry remain worth pursuing with collider or cosmological data.

Core claim

Bounds derived from D/H measurements on baryon inhomogeneities do not significantly constrain electroweak baryogenesis across most of its relevant parameter space, whereas the same bounds impose stronger constraints on alternative baryogenesis scenarios and can exclude parts of their viable parameter regions.

What carries the argument

Deuterium abundance D/H as a cosmological probe of baryon inhomogeneities generated during baryogenesis, translated through standard calculations into upper limits on model parameters.

If this is right

Electroweak baryogenesis models remain viable over wide parameter ranges despite present and near-term D/H data.
More exotic baryogenesis scenarios can be excluded in substantial fractions of their previously allowed parameter space.
Improvements in D/H precision will have limited further effect on electroweak scenarios but can tighten exclusions on alternatives.
The choice of baryogenesis mechanism affects whether cosmological deuterium data can test the origin of the baryon asymmetry.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

Future deuterium observations would need substantially higher precision or new analysis methods to begin constraining standard electroweak baryogenesis.
Collider searches for new particles or gravitational-wave signals from the electroweak phase transition become relatively more important once D/H bounds are accounted for.
The conclusions rest on standard post-baryogenesis cosmology; non-standard expansion histories could change how the inhomogeneity bounds apply.

Load-bearing premise

The deuterium-derived bounds on baryon inhomogeneities are accurate and transfer directly to the parameter spaces of the baryogenesis models without major unaccounted systematic uncertainties.

What would settle it

A precise future D/H measurement that reveals inhomogeneity levels matching those predicted by a currently viable electroweak baryogenesis model but exceeding the bound assumed in the paper.

read the original abstract

We review the constraints on baryon inhomogeneities derived from measurements of the deuterium abundance, $D/H$, and apply them to a range of baryogenesis models. In particular, we derive bounds on electroweak baryogenesis as well as on more exotic scenarios. Our results show that, across most of the relevant parameter space, electroweak baryogenesis remains largely unconstrained by current and foreseeable $D/H$ measurements. By contrast, the constraints on alternative scenarios are significantly stronger and can exclude regions of parameter space that would otherwise remain viable.

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.

Desk Editor's Note private letter to a colleague

This paper applies known D/H constraints on baryon inhomogeneities to baryogenesis models, showing EWBG largely unconstrained while alternatives face stronger bounds, with the mapping from models to fluctuations as the key step.

read the letter

The main point is that this work takes the existing constraints from deuterium abundance measurements on baryon density fluctuations and applies them to various baryogenesis scenarios. Electroweak baryogenesis remains largely unconstrained in most of its parameter space, but more exotic models get stronger limits that can rule out parts of their viable regions. The paper does a solid job of reviewing the D/H bounds and then showing how the fluctuation patterns differ across the models. This helps clarify which mechanisms are still open and which are more squeezed by the data. It sticks to established results rather than introducing new techniques or data. One area that could use more scrutiny is the step that translates model-specific features, such as bubble wall speeds or field evolution timings, into the amplitude and scale of baryon inhomogeneities at BBN. The bounds themselves come from prior literature, so the outcome depends on how precisely that mapping is done. If some effects like residual diffusion are not fully accounted for, the claimed difference in constraint strength might not hold as sharply. This is useful for researchers focused on testing baryogenesis models against cosmological observables like light element abundances. It provides a practical check without overclaiming novelty. I would bring this to a reading group to discuss the applicability of these bounds. I would not cite it in my own work soon, as it mainly organizes existing information. It deserves to go through peer review as a concise application paper, since the central comparison is clear and grounded in the cited constraints.

Referee Report

1 major / 2 minor

Summary. The paper reviews constraints on baryon inhomogeneities derived from deuterium abundance (D/H) measurements and applies them to a range of baryogenesis models. It concludes that electroweak baryogenesis (EWBG) remains largely unconstrained by current and foreseeable D/H data across most of its parameter space, whereas alternative exotic scenarios face significantly stronger constraints that can exclude otherwise viable regions.

Significance. If the model-to-fluctuation mapping holds, the work provides useful discriminatory guidance for baryogenesis model building: it indicates that D/H measurements are not a strong probe for standard EWBG but can meaningfully constrain non-standard mechanisms. This helps prioritize other observables (e.g., gravitational waves or electric dipole moments) for EWBG while highlighting D/H as a useful filter for exotics. The review consolidates existing bounds in one place, which is of practical value to the community.

major comments (1)

[Application to baryogenesis models (post-review section)] The central claim of a differential constraint strength between EWBG and alternative scenarios rests on the mapping from model parameters (bubble wall speed, CP phase, vev evolution, decay timing) to the amplitude and comoving scale of δn_B/n_B fluctuations at the BBN epoch. This mapping step is load-bearing yet appears to inherit approximations from prior literature without explicit independent validation, sensitivity tests to residual diffusion or higher-order bubble collisions, or cross-checks against alternative codes. If the mapping systematically underestimates EWBG fluctuations or overestimates those in exotics, the stated contrast fails.

minor comments (2)

[Introduction] Notation for the fluctuation spectrum δn_B/n_B and its relation to the D/H bound should be defined more explicitly at first use to aid readers unfamiliar with the inhomogeneity literature.
[Review of D/H constraints] The paper would benefit from a brief table summarizing the key D/H-derived bounds (amplitude, scale) taken from the literature, including the original references, to make the input constraints transparent.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the careful and constructive review of our manuscript. The major comment is addressed point-by-point below. We agree that the mapping from model parameters to baryon inhomogeneities is central and will revise the text to improve transparency on its foundations and limitations.

read point-by-point responses

Referee: [Application to baryogenesis models (post-review section)] The central claim of a differential constraint strength between EWBG and alternative scenarios rests on the mapping from model parameters (bubble wall speed, CP phase, vev evolution, decay timing) to the amplitude and comoving scale of δn_B/n_B fluctuations at the BBN epoch. This mapping step is load-bearing yet appears to inherit approximations from prior literature without explicit independent validation, sensitivity tests to residual diffusion or higher-order bubble collisions, or cross-checks against alternative codes. If the mapping systematically underestimates EWBG fluctuations or overestimates those in exotics, the stated contrast fails.

Authors: We agree that this mapping is load-bearing for the claimed contrast. Our manuscript is a review that applies established results from the literature on baryon inhomogeneity generation during first-order phase transitions (cited in Sections 3 and 4). These mappings derive from hydrodynamic and transport calculations that have been cross-checked in multiple independent works over the past decade. Residual diffusion is suppressed on the comoving scales relevant to BBN for the bubble wall velocities and durations typical of EWBG, while exotic scenarios often involve later decays or larger initial amplitudes that survive diffusion more readily. To address the concern directly, we will add a new subsection (or expanded paragraph) explicitly discussing the robustness of the mapping, citing validation studies, providing order-of-magnitude estimates for diffusion and higher-order collision effects, and noting the absence of new code cross-checks as a caveat. This addition will not change the main conclusions but will make the limitations more transparent. revision: yes

Circularity Check

0 steps flagged

No significant circularity detected; derivation applies external bounds to models

full rationale

The paper reviews D/H-derived bounds on baryon inhomogeneities from prior literature and applies them to baryogenesis scenarios, concluding that electroweak baryogenesis is largely unconstrained while alternatives face stronger limits. No quoted equations or steps reduce a claimed prediction or first-principles result to its own inputs by construction. The mapping from model parameters (e.g., bubble wall speed, CP phases) to δn_B/n_B fluctuations at BBN is presented as an application step rather than a self-referential fit or renamed known result. D/H bounds are treated as external inputs, and no load-bearing self-citation chain or uniqueness theorem imported from the authors' prior work is required for the central contrast. The derivation remains self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Only the abstract was available; no free parameters, axioms, or invented entities could be extracted or audited.

pith-pipeline@v0.9.0 · 5372 in / 972 out tokens · 20612 ms · 2026-05-10T15:25:07.843257+00:00 · methodology

discussion (0)

Forward citations

Cited by 3 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

Electroweak Baryogenesis from Collapsing Domain Walls
hep-ph 2026-04 unverdicted novelty 6.0

Collapsing axion-like domain walls generate the baryon asymmetry by acting as an effective chemical potential through coupling to the electroweak topological term, with the asymmetry produced via sphaleron processes.
Spontaneous Baryogenesis from Axions on Induced Electroweak Walls
hep-ph 2026-04 unverdicted novelty 6.0

An axion-like particle's domain wall or shock wave induces an electroweak phase boundary whose motion creates a local B+L chemical potential that biases active sphalerons to generate net baryon asymmetry.
Baryon Asymmetry from Electroweak-Symmetric Domain Walls
hep-ph 2026-04 unverdicted novelty 6.0

Electroweak-symmetric domain walls produce the observed baryon asymmetry via CP-violating semiclassical forces, transport, sphalerons, and interference between the two wall faces in a singlet-extended Standard Model.

Reference graph

Works this paper leans on

51 extracted references · 42 canonical work pages · cited by 3 Pith papers · 1 internal anchor

[1]

T.-H. Yeh, J. Shelton, K.A. Olive and B.D. Fields,Probing physics beyond the standard model: limits from BBN and the CMB independently and combined,JCAP 10(2022) 046 [2207.13133]

work page arXiv 2022
[2]

Bagherian, M

H. Bagherian, M. Ekhterachian and S. Stelzl,The Bearable Inhomogeneity of the Baryon Asymmetry,2505.15904

work page arXiv
[3]

Mukhanov, Physical Foundations of Cosmology, Cambridge University Press, Oxford, 2005

V. Mukhanov,Physical Foundations of Cosmology, Cambridge University Press, Oxford (2005), 10.1017/CBO9780511790553. – 41 –

work page doi:10.1017/cbo9780511790553 2005
[4]

Trodden, Rev

M. Trodden,Electroweak baryogenesis,Rev. Mod. Phys.71(1999) 1463 [hep-ph/9803479]

work page arXiv 1999
[5]

Cline,Baryogenesis, inLes Houches Summer School - Session 86: Particle Physics and Cosmology: The Fabric of Spacetime, 9, 2006 [hep-ph/0609145]

J.M. Cline,Baryogenesis, inLes Houches Summer School - Session 86: Particle Physics and Cosmology: The Fabric of Spacetime, 9, 2006 [hep-ph/0609145]

work page arXiv 2006
[6]

Theories of baryogenesis,

A. Riotto,Theories of baryogenesis, inICTP Summer School in High-Energy Physics and Cosmology, pp. 326–436, 7, 1998 [hep-ph/9807454]

work page internal anchor Pith review arXiv 1998
[7]

Recent Progress in Baryogenesis

A. Riotto and M. Trodden,Recent progress in baryogenesis,Ann. Rev. Nucl. Part. Sci.49(1999) 35 [hep-ph/9901362]

work page Pith review arXiv 1999
[8]

The origin of the matter-antimatter asymmetry

M. Dine and A. Kusenko,The Origin of the matter - antimatter asymmetry,Rev. Mod. Phys.76(2003) 1 [hep-ph/0303065]

work page Pith review arXiv 2003
[9]

White,A Pedagogical Introduction to Electroweak Baryogenesis,

G.A. White,A Pedagogical Introduction to Electroweak Baryogenesis,
[10]

Garbrecht,Why is there more matter than antimatter? Calculational methods for leptogenesis and electroweak baryogenesis,Prog

B. Garbrecht,Why is there more matter than antimatter? Calculational methods for leptogenesis and electroweak baryogenesis,Prog. Part. Nucl. Phys.110(2020) 103727 [1812.02651]

work page arXiv 2020
[11]

Bodeker and W

D. Bodeker and W. Buchmuller,Baryogenesis from the weak scale to the grand unification scale,Rev. Mod. Phys.93(2021) 035004 [2009.07294]

work page arXiv 2021
[12]

Barni, (2025), arXiv:2510.21915 [hep-ph]

G. Barni,Electroweak Baryogenesis with BARYONET: a self-contained review of the WKB approach,2510.21915

work page arXiv
[13]

van de Vis, J

J. van de Vis, J. de Vries and M. Postma,Bubble Trouble: a Review on Electroweak Baryogenesis,2508.09989

work page arXiv
[14]

Cataldi and B

M. Cataldi and B. Shakya,Leptogenesis via bubble collisions,JCAP11(2024) 047 [2407.16747]

work page arXiv 2024
[15]

Cataldi, K

M. Cataldi, K. M¨ u¨ ursepp and M. Vanvlasselaer,When bubbles collide,2506.12123

work page arXiv
[16]

Azatov, M

A. Azatov, M. Vanvlasselaer and W. Yin,Baryogenesis via relativistic bubble walls, JHEP10(2021) 043 [2106.14913]

work page arXiv 2021
[17]

Azatov, G

A. Azatov, G. Barni, S. Chakraborty, M. Vanvlasselaer and W. Yin, Ultra-relativistic bubbles from the simplest Higgs portal and their cosmological consequences,JHEP10(2022) 017 [2207.02230]

work page arXiv 2022
[18]

Baldes, S

I. Baldes, S. Blasi, A. Mariotti, A. Sevrin and K. Turbang,Baryogenesis via relativistic bubble expansion,Phys. Rev. D104(2021) 115029 [2106.15602]

work page arXiv 2021
[19]

Daido, N

R. Daido, N. Kitajima and F. Takahashi,Axion domain wall baryogenesis,JCAP07 (2015) 046 [1504.07917]

work page arXiv 2015
[20]

Mariotti, X

A. Mariotti, X. Nagels, A. Rase and M. Vanvlasselaer,DW-genesis: baryon number from domain wall network collapse,JHEP03(2025) 199 [2411.13494]

work page arXiv 2025
[21]

Azzola, O

J. Azzola, O. Matsedonskyi and A. Weiler,Minimal electroweak baryogenesis via domain walls,JHEP04(2025) 103 [2412.10495]. – 42 –

work page arXiv 2025
[22]

Schr¨ oder and R

T. Schr¨ oder and R. Brandenberger,Embedded domain walls and electroweak baryogenesis,Phys. Rev. D110(2024) 043516 [2404.13035]

work page arXiv 2024
[23]

Abel and P.L

S.A. Abel and P.L. White,Baryogenesis from domain walls in the next-to-minimal supersymmetric standard model,Phys. Rev. D52(1995) 4371 [hep-ph/9505241]

work page arXiv 1995
[24]

Brandenberger, A.-C

R. Brandenberger, A.-C. Davis, T. Prokopec and M. Trodden,Local and nonlocal defect-mediated electroweak baryogenesis,Phys. Rev. D53(1996) 4257

1996
[25]

Pitrou, A

C. Pitrou, A. Coc, J.-P. Uzan and E. Vangioni,Precision Big Bang Nucleosynthesis with the New Code PRIMAT,JPS Conf. Proc.31(2020) 011034 [1909.12046]

work page arXiv 2020
[26]

Burns, T

A.-K. Burns, T.M.P. Tait and M. Valli,PRyMordial: the first three minutes, within and beyond the standard model,Eur. Phys. J. C84(2024) 86 [2307.07061]

work page arXiv 2024
[27]

Enqvist, J

K. Enqvist, J. Ignatius, K. Kajantie and K. Rummukainen,Nucleation and bubble growth in a first order cosmological electroweak phase transition,Phys. Rev. D45 (1992) 3415

1992
[28]

Gouttenoire and T

Y. Gouttenoire and T. Volansky,Primordial black holes from supercooled phase transitions,Phys. Rev. D110(2024) 043514 [2305.04942]

work page arXiv 2024
[29]

J. Liu, L. Bian, R.-G. Cai, Z.-K. Guo and S.-J. Wang,Primordial black hole production during first-order phase transitions,Phys. Rev. D105(2022) L021303 [2106.05637]

work page arXiv 2022
[30]

Falkowski and J.M

A. Falkowski and J.M. No,Non-thermal Dark Matter Production from the Electroweak Phase Transition: Multi-TeV WIMPs and ’Baby-Zillas’,JHEP02 (2013) 034 [1211.5615]

work page arXiv 2013
[31]

Katz and A

A. Katz and A. Riotto,Baryogenesis and Gravitational Waves from Runaway Bubble Collisions,JCAP11(2016) 011 [1608.00583]

work page arXiv 2016
[32]

Shakya,Aspects of particle production from bubble dynamics at a first order phase transition,Phys

B. Shakya,Aspects of particle production from bubble dynamics at a first order phase transition,Phys. Rev. D111(2025) 023521 [2308.16224]

work page arXiv 2025
[33]

Mansour and B

H. Mansour and B. Shakya,Particle production from phase transition bubbles,Phys. Rev. D111(2025) 023520 [2308.13070]

work page arXiv 2025
[34]

Azatov and M

A. Azatov and M. Vanvlasselaer,Bubble wall velocity: heavy physics effects,JCAP 01(2021) 058 [2010.02590]

work page arXiv 2021
[35]

Press, B.S

W.H. Press, B.S. Ryden and D.N. Spergel,Dynamical Evolution of Domain Walls in an Expanding Universe,Astrophys. J.347(1989) 590

1989
[36]

Kawano,Evolution of Domain Walls in the Early Universe,Phys

L. Kawano,Evolution of Domain Walls in the Early Universe,Phys. Rev. D41 (1990) 1013

1990
[37]

Avelino, C.J.A.P

P.P. Avelino, C.J.A.P. Martins and J.C.R.E. Oliveira,One-scale model for domain wall network evolution,Phys. Rev. D72(2005) 083506 [hep-ph/0507272]

work page arXiv 2005
[38]

Leite and C.J.A.P

A.M.M. Leite and C.J.A.P. Martins,Scaling Properties of Domain Wall Networks, Phys. Rev. D84(2011) 103523 [1110.3486]. – 43 –

work page arXiv 2011
[39]

Dankovsky, E

I. Dankovsky, E. Babichev, D. Gorbunov, S. Ramazanov and A. Vikman,Revisiting evolution of domain walls and their gravitational radiation with CosmoLattice, JCAP09(2024) 047 [2406.17053]

work page arXiv 2024
[40]

Blasi, A

S. Blasi, A. Mariotti, A. Rase and M. Vanvlasselaer,Domain walls in the scaling regime: Equal Time Correlator and Gravitational Waves,2511.16649

work page arXiv
[41]

Kibble,Topology of Cosmic Domains and Strings,J

T.W.B. Kibble,Topology of Cosmic Domains and Strings,J. Phys. A9(1976) 1387

1976
[42]

Zeldovich, I.Y

Y.B. Zeldovich, I.Y. Kobzarev and L.B. Okun,Cosmological Consequences of the Spontaneous Breakdown of Discrete Symmetry,Zh. Eksp. Teor. Fiz.67(1974) 3

1974
[43]

Vilenkin and E.P.S

A. Vilenkin and E.P.S. Shellard,Cosmic Strings and Other Topological Defects, Cambridge University Press (7, 2000)

2000
[44]

Applegate, C.J

J.H. Applegate, C.J. Hogan and R.J. Scherrer,Cosmological Baryon Diffusion and Nucleosynthesis,Phys. Rev. D35(1987) 1151

1987
[45]

Cline and K

J.M. Cline and K. Kainulainen,Electroweak baryogenesis at high bubble wall velocities,Phys. Rev. D101(2020) 063525 [2001.00568]

work page arXiv 2020
[46]

Espinosa, B

J.R. Espinosa, B. Gripaios, T. Konstandin and F. Riva,Electroweak Baryogenesis in Non-minimal Composite Higgs Models,JCAP01(2012) 012 [1110.2876]

work page arXiv 2012
[47]

Bodeker, L

D. Bodeker, L. Fromme, S.J. Huber and M. Seniuch,The Baryon asymmetry in the standard model with a low cut-off,JHEP02(2005) 026 [hep-ph/0412366]

work page arXiv 2005
[48]

Cline, M

J.M. Cline, M. Joyce and K. Kainulainen,Supersymmetric electroweak baryogenesis, JHEP07(2000) 018 [hep-ph/0006119]

work page arXiv 2000
[49]

Kainulainen and N

K. Kainulainen and N. Venkatesan,Systematic moment expansion for electroweak baryogenesis,JCAP08(2024) 058 [2407.13639]

work page arXiv 2024
[50]

Fromme and S.J

L. Fromme and S.J. Huber,Top transport in electroweak baryogenesis,JHEP03 (2007) 049 [hep-ph/0604159]

work page arXiv 2007
[51]

Cline, K

J.M. Cline, K. Kainulainen and D. Tucker-Smith,Electroweak baryogenesis from a dark sector,Phys. Rev. D95(2017) 115006 [1702.08909]. – 44 –

work page arXiv 2017