pith. sign in

arxiv: 2606.13514 · v1 · pith:BW43ETZKnew · submitted 2026-06-11 · ✦ hep-ph · gr-qc

Electroweak First-Order Phase Transition Triggered by Non-Gaussian Fluctuations of a mathbb{Z}₂-Symmetric Spectator Scalar

Pith reviewed 2026-06-27 06:18 UTC · model grok-4.3

classification ✦ hep-ph gr-qc
keywords electroweak phase transitionfirst-order phase transitionnon-Gaussian fluctuationsspectator scalardark mattergravitational wavesprimordial fluctuationsZ2 symmetry
0
0 comments X

The pith

Non-Gaussian fluctuations of a spectator scalar can trigger a strong first-order electroweak phase transition.

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

The paper proposes that non-Gaussian primordial fluctuations in a Z2-symmetric spectator scalar field can locally alter the Higgs boson's thermal mass in the early universe. This alteration increases the height of the thermal barrier between the symmetric and electroweak-broken phases, making the transition first-order and strong rather than a smooth crossover. Because non-Gaussian distributions produce more extreme fluctuations than Gaussian ones, a large enough volume of the universe experiences this strong transition. The same scalar field later oscillates to account for the observed dark matter density. The transition also generates a stochastic background of gravitational waves in a frequency window accessible to planned space-based detectors.

Core claim

We propose a novel mechanism to trigger a first-order cosmological electroweak phase transition using non-Gaussian primordial fluctuations of a Z2-symmetric spectator scalar field. We show that the large fluctuations of the spectator field can modify the Higgs thermal mass and enhance the thermal barrier, thereby enabling a strong first-order phase transition. Non-Gaussianities in the primordial fluctuation spectrum significantly increase the probability of large-amplitude fluctuations, allowing a substantial fraction of the Universe to undergo the transition. The spectator field also naturally serves as a cold dark matter candidate through its coherent oscillations, reproducing the observed

What carries the argument

The non-Gaussian primordial fluctuations of the Z2-symmetric spectator scalar, which act as local shifts that raise the Higgs thermal mass and strengthen the effective potential barrier during the electroweak epoch.

If this is right

  • A substantial fraction of the Universe undergoes the strong first-order electroweak phase transition.
  • The spectator scalar field accounts for the observed dark matter relic abundance via its later coherent oscillations.
  • The phase transition produces a stochastic gravitational wave background that peaks between 10^{-3} and 10^{-1} Hz.

Where Pith is reading between the lines

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

  • The level of non-Gaussianity needed could be tested against constraints from smaller-scale primordial fluctuation observations.
  • If the transition is sufficiently strong, it could be combined with CP-violating effects to also explain the observed matter-antimatter asymmetry.
  • Independent confirmation could come from gravitational wave detectors operating in the predicted frequency band even without direct detection of the scalar particle.

Load-bearing premise

The spectator scalar's non-Gaussian fluctuations persist unmodified until the electroweak epoch and can be treated as a local shift to the Higgs thermal mass without significant back-reaction.

What would settle it

Future measurements showing that primordial fluctuations are Gaussian with amplitudes too small to produce the required barrier enhancement, or the absence of a stochastic gravitational wave background in the 10^{-3} to 10^{-1} Hz range.

read the original abstract

We propose a novel mechanism to trigger a first-order cosmological electroweak phase transition using non-Gaussian primordial fluctuations of a $\mathbb{Z}_2$-symmetric spectator scalar field. We show that the large fluctuations of the spectator field can modify the Higgs thermal mass and enhance the thermal barrier, thereby enabling a strong first-order phase transition. Non-Gaussianities in the primordial fluctuation spectrum significantly increase the probability of large-amplitude fluctuations, allowing a substantial fraction of the Universe to undergo the transition. The spectator field also naturally serves as a cold dark matter candidate through its coherent oscillations, reproducing the observed relic abundance. The resulting stochastic gravitational wave background peaks in the $10^{-3}$-$10^{-1}$ Hz band, making it detectable by future space-based interferometers.

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

3 major / 2 minor

Summary. The manuscript proposes a novel mechanism in which non-Gaussian primordial fluctuations of a Z_2-symmetric spectator scalar modify the Higgs thermal mass, enhancing the thermal barrier and enabling a strong first-order electroweak phase transition in a substantial fraction of the Universe; the same spectator is claimed to account for cold dark matter with the observed relic abundance, producing a stochastic gravitational-wave background peaking in the 10^{-3}–10^{-1} Hz band.

Significance. If the decoupling and persistence assumptions hold, the work would link primordial non-Gaussianities directly to a strong electroweak transition, dark-matter production, and an observable GW signal without new TeV-scale degrees of freedom. The explicit incorporation of non-Gaussian tails to increase the probability of suitable patches is a clear technical strength.

major comments (3)
  1. [§3] §3 (model and effective potential): the local modification m_H²(T,φ(x)) via the (λ/2)φ²|H|² operator is introduced, but no evolution equation or Boltzmann-equation estimate is supplied to demonstrate that the required fluctuation amplitude leaves the spectator frozen and decoupled down to T∼100 GeV with negligible thermalization or damping of the non-Gaussian tail.
  2. [§4] §4 (phase-transition probability): the fraction of the Universe undergoing the strong transition is computed from the non-Gaussian tail, yet the calculation assumes the fluctuations act as a static background shift; back-reaction on the metric or on φ itself is not quantified for the amplitudes needed to reproduce the observed relic density.
  3. [§5] §5 (dark-matter relic): the statement that the spectator “naturally” reproduces the observed relic abundance is presented without showing that the mass and initial amplitude are fixed by the same parameters that control the phase-transition strength; at least one parameter appears adjusted to match Ω_DM rather than predicted.
minor comments (2)
  1. The abstract would be strengthened by quoting the explicit form of the spectator-Higgs coupling and the condition that keeps φ out of equilibrium.
  2. Notation for the non-Gaussian parameter (e.g., f_NL or equivalent) should be defined at first use and kept consistent between the fluctuation spectrum and the probability integral.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the thorough review and constructive feedback on our manuscript. We address each major comment below, providing clarifications and indicating where revisions will be made to strengthen the presentation.

read point-by-point responses
  1. Referee: [§3] §3 (model and effective potential): the local modification m_H²(T,φ(x)) via the (λ/2)φ²|H|² operator is introduced, but no evolution equation or Boltzmann-equation estimate is supplied to demonstrate that the required fluctuation amplitude leaves the spectator frozen and decoupled down to T∼100 GeV with negligible thermalization or damping of the non-Gaussian tail.

    Authors: We agree that an explicit estimate would improve clarity. The Z₂ symmetry and small portal coupling λ ensure the spectator remains decoupled, with thermalization rate Γ_thermal ~ λ² T suppressed below the Hubble rate for λ ≲ 10^{-3} at T ~ 100 GeV. The non-Gaussian tail is preserved because the field is effectively massless and frozen after inflation. We will add a short Boltzmann-equation estimate and decoupling condition in the revised §3. revision: yes

  2. Referee: [§4] §4 (phase-transition probability): the fraction of the Universe undergoing the strong transition is computed from the non-Gaussian tail, yet the calculation assumes the fluctuations act as a static background shift; back-reaction on the metric or on φ itself is not quantified for the amplitudes needed to reproduce the observed relic density.

    Authors: The static-background approximation holds because the fluctuation energy density remains subdominant to radiation in the relevant patches at T ~ 100 GeV, with δρ/ρ ≪ 1. Metric back-reaction is negligible on sub-horizon scales relevant for the local transition. We will add a brief quantification of back-reaction effects and confirm the approximation's validity in the revised §4. revision: yes

  3. Referee: [§5] §5 (dark-matter relic): the statement that the spectator “naturally” reproduces the observed relic abundance is presented without showing that the mass and initial amplitude are fixed by the same parameters that control the phase-transition strength; at least one parameter appears adjusted to match Ω_DM rather than predicted.

    Authors: The spectator mass m_φ and initial amplitude are fixed by the non-Gaussianity parameters and the portal coupling required for the phase-transition strength in §3–4. Section 5 demonstrates that these same values yield Ω_DM h² ≈ 0.12 via coherent oscillations without additional tuning, as the relic density is a direct output of the parameter set chosen for the transition probability. revision: no

Circularity Check

0 steps flagged

No circularity: central mechanism uses external fluctuation statistics and standard thermal potential without self-referential reduction.

full rationale

The derivation invokes non-Gaussian primordial fluctuations to shift the Higgs thermal mass via a spectator coupling, then computes the resulting barrier and transition probability. The relic abundance statement is a standard parameter choice for the spectator mass/amplitude to match Omega_DM after the mechanism is defined; it does not enter the phase-transition equations as a fitted input renamed as prediction. No self-citations, uniqueness theorems, or ansatze imported from prior author work appear in the provided text. The decoupling assumption is an explicit modeling choice, not a definitional loop. The paper remains self-contained against external benchmarks for the fluctuation spectrum and thermal effective potential.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 1 invented entities

The central claim rests on the introduction of a new scalar field whose primordial fluctuations are assumed to survive to the electroweak scale and on the choice of parameters that set the fluctuation amplitude and scalar mass to achieve both the phase transition and the observed dark-matter density.

free parameters (2)
  • non-Gaussian fluctuation amplitude
    The size of the fluctuations required to produce a sufficient barrier height is not derived from first principles and must be chosen to enable the transition in a substantial volume fraction.
  • spectator scalar mass
    The mass parameter is adjusted so that coherent oscillations after the transition reproduce the observed dark-matter relic abundance.
axioms (2)
  • domain assumption The spectator scalar possesses an exact Z2 symmetry.
    Invoked in the title and abstract to ensure the field remains stable and can serve as dark matter.
  • domain assumption Primordial fluctuations of the spectator are non-Gaussian and persist unmodified until the electroweak epoch.
    Central premise that allows large-amplitude regions to modify the Higgs thermal mass.
invented entities (1)
  • Z2-symmetric spectator scalar field no independent evidence
    purpose: To generate non-Gaussian fluctuations that trigger the first-order phase transition and to provide the cold dark matter relic density via coherent oscillations.
    New field postulated to solve the electroweak phase transition problem while simultaneously addressing dark matter.

pith-pipeline@v0.9.1-grok · 5663 in / 1719 out tokens · 29067 ms · 2026-06-27T06:18:46.442500+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

128 extracted references · 56 linked inside Pith

  1. [1]

    D’Onofrio, K

    M. D’Onofrio, K. Rummukainen, and A. Tranberg,Sphaleron Rate in the Minimal Standard Model, Phys. Rev. Lett.113(2014), no. 14 141602, [1404.3565]

  2. [2]

    D. E. Morrissey and M. J. Ramsey-Musolf,Electroweak baryogenesis,New J. Phys.14(2012) 125003, [1206.2942]

  3. [3]

    Bianet al.,Gravitational wave cosmology,Sci

    L. Bianet al.,Gravitational wave cosmology,Sci. China Phys. Mech. Astron.69(2026), no. 1 210401, [2505.19747]

  4. [4]

    V. A. Kuzmin, V. A. Rubakov, and M. E. Shaposhnikov,On the Anomalous Electroweak Baryon Number Nonconservation in the Early Universe,Phys. Lett. B155(1985) 36

  5. [5]

    A. G. Cohen, D. B. Kaplan, and A. E. Nelson,WEAK SCALE BARYOGENESIS,Phys. Lett. B245(1990) 561–564

  6. [6]

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

  7. [7]

    Witten,Cosmic Separation of Phases,Phys

    E. Witten,Cosmic Separation of Phases,Phys. Rev. D30(1984) 272–285. – 26 –

  8. [8]

    Kamionkowski, A

    M. Kamionkowski, A. Kosowsky, and M. S. Turner,Gravitational radiation from first order phase transitions,Phys. Rev. D49(1994) 2837–2851, [astro-ph/9310044]

  9. [9]

    Grojean and G

    C. Grojean and G. Servant,Gravitational Waves from Phase Transitions at the Electroweak Scale and Beyond,Phys. Rev. D75(2007) 043507, [hep-ph/0607107]

  10. [10]

    Capriniet al.,Science with the space-based interferometer eLISA

    C. Capriniet al.,Science with the space-based interferometer eLISA. II: Gravitational waves from cosmological phase transitions,JCAP04(2016) 001, [1512.06239]

  11. [11]

    D. J. Weir,Gravitational waves from a first order electroweak phase transition: a brief review, Phil. Trans. Roy.Soc. Lond. A376(2018), no. 2114 20170126, [1705.01783]. [Erratum: Phil.Trans.Roy.Soc.Lond.A 381, 20230212 (2023)]

  12. [12]

    Athron, C

    P. Athron, C. Balázs, A. Fowlie, L. Morris, and L. Wu,Cosmological phase transitions: From perturbative particle physics to gravitational waves,Prog. Part. Nucl. Phys.135(2024) 104094, [2305.02357]. [15]LISACollaboration, P. Amaro-Seoane et al.,Laser Interferometer Space Antenna, 1702.00786. [16]LISA Cosmology W orking GroupCollaboration, P. Auclair et al...

  13. [13]

    Z. Luo, Z. Guo, G. Jin, Y. Wu, and W. Hu,A brief analysis to Taiji: Science and technology, Results Phys.16(2020) 102918

  14. [14]

    Satoet al.,The status of DECIGO,J

    S. Satoet al.,The status of DECIGO,J. Phys. Conf. Ser.840(2017), no. 1 012010

  15. [15]

    Crowder and N

    J. Crowder and N. J. Cornish,Beyond LISA: Exploring future gravitational wave missions, Phys. Rev. D72(2005) 083005, [gr-qc/0506015]

  16. [16]

    Bertone and D

    G. Bertone and D. Hooper,History of dark matter,Rev. Mod. Phys.90(2018), no. 4 045002, [1605.04909]. [22]PlanckCollaboration, N. Aghanim et al.,Planck 2018 results. VI. Cosmological parameters, Astron. Astrophys.641(2020) A6, [1807.06209]. [Erratum: Astron.Astrophys. 652, C4 (2021)]

  17. [17]

    B. W. Lee and S. Weinberg,Cosmological Lower Bound on Heavy Neutrino Masses,Phys. Rev. Lett.39(1977) 165–168

  18. [18]

    Hut,Limits on Masses and Number of Neutral Weakly Interacting Particles,Phys

    P. Hut,Limits on Masses and Number of Neutral Weakly Interacting Particles,Phys. Lett. B 69(1977) 85

  19. [19]

    Arcadi, M

    G. Arcadi, M. Dutra, P. Ghosh, M. Lindner, Y. Mambrini, M. Pierre, S. Profumo, and F. S. Queiroz,The waning of the WIMP? A review of models, searches, and constraints,Eur. Phys. J. C78(2018), no. 3 203, [1703.07364]

  20. [20]

    D. S. Akeribet al.,Snowmass2021 Cosmic Frontier Dark Matter Direct Detection to the Neutrino Fog, inSnowmass 2021, 3, 2022.2203.08084. [27]XENONCollaboration, E. Aprile et al.,First Search for Light Dark Matter in the Neutrino Fog with XENONnT,Phys. Rev. Lett.134(2025), no. 11 111802, [2409.17868]. – 27 – [28]P ANDA-X, PandaXCollaboration, A. Abdukerim et...

  21. [21]

    Xia and L

    Q. Xia and L. Canonica,Progress and prospects in the underground laboratories’ search for dark matter,Commun. Phys.9(2026), no. 1 105

  22. [22]

    Profumo, L

    S. Profumo, L. Giani, and O. F. Piattella,An Introduction to Particle Dark Matter,Universe 5(2019), no. 10 213, [1910.05610]

  23. [23]

    Gouttenoire,Beyond the Standard Model Cocktail

    Y. Gouttenoire,Beyond the Standard Model Cocktail. Springer Theses. Springer, Cham, 2022

  24. [24]

    Baldes, M

    I. Baldes, M. Dichtl, Y. Gouttenoire, and F. Sala,Ultrahigh-Energy Particle Collisions and Heavy Dark Matter at Phase Transitions,Phys. Rev. Lett.134(2025), no. 6 061001, [2306.15555]

  25. [25]

    Cirelli, A

    M. Cirelli, A. Strumia, and J. Zupan,Dark Matter,2406.01705

  26. [26]

    Profumo, M

    S. Profumo, M. J. Ramsey-Musolf, and G. Shaughnessy,Singlet Higgs phenomenology and the electroweak phase transition,JHEP08(2007) 010, [0705.2425]

  27. [27]

    J. R. Espinosa and M. Quiros,Novel Effects in Electroweak Breaking from a Hidden Sector, Phys. Rev. D76(2007) 076004, [hep-ph/0701145]

  28. [28]

    Barger, P

    V. Barger, P. Langacker, M. McCaskey, M. J. Ramsey-Musolf, and G. Shaughnessy,LHC Phenomenology of an Extended Standard Model with a Real Scalar Singlet,Phys. Rev. D77 (2008) 035005, [0706.4311]

  29. [29]

    J. R. Espinosa, T. Konstandin, and F. Riva,Strong Electroweak Phase Transitions in the Standard Model with a Singlet,Nucl. Phys. B854(2012) 592–630, [1107.5441]

  30. [30]

    J. M. Cline and K. Kainulainen,Electroweak baryogenesis and dark matter from a singlet Higgs, JCAP01(2013) 012, [1210.4196]

  31. [31]

    J. M. No and M. Ramsey-Musolf,Probing the Higgs Portal at the LHC Through Resonant di-Higgs Production,Phys. Rev. D89(2014), no. 9 095031, [1310.6035]

  32. [32]

    Profumo, M

    S. Profumo, M. J. Ramsey-Musolf, C. L. Wainwright, and P. Winslow,Singlet-catalyzed electroweak phase transitions and precision Higgs boson studies,Phys. Rev. D91(2015), no. 3 035018, [1407.5342]

  33. [33]

    Jiang, L

    M. Jiang, L. Bian, W. Huang, and J. Shu,Impact of a complex singlet: Electroweak baryogenesis and dark matter,Phys. Rev. D93(2016), no. 6 065032, [1502.07574]

  34. [34]

    Chiang, M

    C.-W. Chiang, M. J. Ramsey-Musolf, and E. Senaha,Standard Model with a Complex Scalar Singlet: Cosmological Implications and Theoretical Considerations,Phys. Rev. D97(2018), no. 1 015005, [1707.09960]

  35. [35]

    Grzadkowski and D

    B. Grzadkowski and D. Huang,SpontaneousCP-Violating Electroweak Baryogenesis and Dark Matter from a Complex Singlet Scalar,JHEP08(2018) 135, [1807.06987]

  36. [36]

    Chiang and B.-Q

    C.-W. Chiang and B.-Q. Lu,First-order electroweak phase transition in a complex singlet model withZ 3 symmetry, JHEP07(2020) 082, [1912.12634]

  37. [37]

    X. Deng, X. Liu, J. Yang, R. Zhou, and L. Bian,Heavy dark matter and Gravitational waves, Phys. Rev. D103(2021), no. 5 055013, [2012.15174]. – 28 –

  38. [38]

    R. Zhou, J. Yang, and L. Bian,Gravitational Waves from first-order phase transition and domain wall,JHEP04(2020) 071, [2001.04741]

  39. [39]

    A. Paul, U. Mukhopadhyay, and D. Majumdar,Gravitational Wave Signatures from Domain Wall and Strong First-Order Phase Transitions in a Two Complex Scalar extension of the Standard Model,JHEP05(2021) 223, [2010.03439]

  40. [40]

    Bian, Y.-L

    L. Bian, Y.-L. Tang, and R. Zhou,FIMP dark matter mediated by a massive gauge boson around the phase transition period and the gravitational waves production,Phys. Rev. D106 (2022), no. 3 035028, [2111.10608]

  41. [41]

    Demidov, D

    S. Demidov, D. Gorbunov, and E. Kriukova,Gravitational waves from first-order electroweak phase transition in a model with light sgoldstinos,JHEP07(2022) 061, [2112.06083]

  42. [42]

    Chaudhuri and J

    A. Chaudhuri and J. Das,Study of entropy production due to electroweak phase transition in Z2 symmetric extension of the Standard Model,Phys. Rev. D106(2022), no. 9 095016, [2206.08699]

  43. [43]

    Y. Xiao, J. M. Yang, and Y. Zhang,Dilution of dark matter relic density in singlet extension models, JHEP02(2023) 008, [2207.14519]

  44. [44]

    Chen, C.-W

    T.-K. Chen, C.-W. Chiang, C.-T. Huang, and B.-Q. Lu,Updated constraints on the Georgi-Machacek model and its electroweak phase transition and associated gravitational waves, Phys. Rev. D106(2022), no. 5 055019, [2205.02064]

  45. [45]

    Lu, C.-W

    B.-Q. Lu, C.-W. Chiang, and D. Huang,Probing WIMPs in space-based gravitational wave experiments, Phys. Lett. B833(2022) 137308, [2205.08380]

  46. [46]

    Chatterjee, A

    A. Chatterjee, A. Datta, and S. Roy,Electroweak phase transition in the Z3-invariant NMSSM: Implications of LHC and Dark matter searches and prospects of detecting the gravitational waves,JHEP06(2022) 108, [2202.12476]

  47. [47]

    Baldes, Y

    I. Baldes, Y. Gouttenoire, and F. Sala,Hot and heavy dark matter from a weak scale phase transition, SciPost Phys.14(2023), no. 3 033, [2207.05096]

  48. [48]

    Ghosh, T

    P. Ghosh, T. Ghosh, and S. Roy,Interplay among gravitational waves, dark matter and collider signals in the singlet scalar extended type-II seesaw model,JHEP10(2023) 057, [2211.15640]

  49. [49]

    Q.-H. Cao, K. Hashino, X.-X. Li, and J.-H. Yue,Multistep phase transition and gravitational wave from general Z2 scalar extensions,Phys. Rev. D111(2025), no. 9 095003, [2212.07756]

  50. [50]

    S. Xu, R. Zhou, W. Cheng, and X. Liu,Dark matter production accompanied by gravitational wave signals during cosmological phase transitions,Eur. Phys. J. C84(2024), no. 7 677, [2312.15752]

  51. [51]

    D. K. Ghosh, K. Mukherjee, and S. Mukherjee,Electroweak phase transition in two scalar singlet model with pNGB dark matter,JHEP01(2025) 078, [2409.00192]

  52. [52]

    D’Eramo, A

    F. D’Eramo, A. Tesi, and V. Vaskonen,Irreducible cosmological backgrounds of a real scalar with a broken symmetry,Phys. Rev. D110(2024), no. 9 095002, [2407.19997]

  53. [53]

    Borah and P

    P. Borah and P. Ghosh,Unveiling the inert Triplet desert region with a pNGB Dark Matter and its Gravitational Wave signatures,2505.16521

  54. [54]

    Srivastava, J

    T. Srivastava, J. Das, A. Ghosh, and A. Chaudhuri,Electroweak phase transition, gravitational – 29 – waves and collider probes in multi-scalar dark matter scenarios,JCAP02(2026) 032, [2507.05917]

  55. [55]

    J. Liu, M. Tanaka, X.-P. Wang, J.-J. Zhang, and Z. Zheng,Scattering entanglement entropy and its implications for electroweak phase transitions,Phys. Rev. D112(2025), no. 1 015028, [2505.06001]

  56. [56]

    Mirzaie, K

    S. Mirzaie, K. Ghorbani, and P. Ghorbani,Fermion dark matter effect on electroweak phase transition, Eur. Phys. J. C85(2025), no. 10 1187, [2502.04265]

  57. [57]

    Robens and R

    T. Robens and R. Santos,BSM: Extended Scalar Sectors, 7, 2025.2507.21910

  58. [58]

    J. Das, S. Niyogi, and T. Srivastava,Revisiting Singlet Fermion Dark Matter with a Scalar Portal: Connecting Higgs Phenomenology and Strong Electroweak Phase Transition, 2601.13147

  59. [59]

    J. M. Cline, K. Kainulainen, and M. Trott,Electroweak Baryogenesis in Two Higgs Doublet Models and B meson anomalies,JHEP11(2011) 089, [1107.3559]

  60. [60]

    G. C. Dorsch, S. J. Huber, K. Mimasu, and J. M. No,Echoes of the Electroweak Phase Transition: Discovering a second Higgs doublet throughA0 →ZH 0, Phys. Rev. Lett.113 (2014), no. 21 211802, [1405.5537]

  61. [61]

    Basler, M

    P. Basler, M. Krause, M. Muhlleitner, J. Wittbrodt, and A. Wlotzka,Strong First Order Electroweak Phase Transition in the CP-Conserving 2HDM Revisited,JHEP02(2017) 121, [1612.04086]

  62. [62]

    G. C. Dorsch, S. J. Huber, K. Mimasu, and J. M. No,The Higgs Vacuum Uplifted: Revisiting the Electroweak Phase Transition with a Second Higgs Doublet,JHEP12(2017) 086, [1705.09186]

  63. [63]

    Zhang, C

    Z. Zhang, C. Cai, X.-M. Jiang, Y.-L. Tang, Z.-H. Yu, and H.-H. Zhang,Phase transition gravitational waves from pseudo-Nambu-Goldstone dark matter and two Higgs doublets,JHEP 05(2021) 160, [2102.01588]

  64. [64]

    M. J. Ramsey-Musolf, V. Q. Tran, and T.-C. Yuan,Gravitational waves and dark matter in the gauged two-Higgs doublet model,JHEP01(2025) 129, [2408.05167]

  65. [65]

    M. Aoki, T. Komatsu, and H. Shibuya,Possibility of a multi-step electroweak phase transition in the two-Higgs doublet models,PTEP2022(2022), no. 6 063B05, [2106.03439]

  66. [66]

    Biekötter and M

    T. Biekötter and M. O. Olea-Romacho,Reconciling Higgs physics and pseudo-Nambu-Goldstone dark matter in the S2HDM using a genetic algorithm,JHEP10 (2021) 215, [2108.10864]

  67. [67]

    Chaudhuri and K

    A. Chaudhuri and K. Kohri,The N2HDM, Entropy Production and Stochastic Gravitational Waves, Nucl. Phys. B1018(2025) 117098, [2404.10288]

  68. [68]

    S. Lee, D. Kim, J.-H. Cho, J. Kim, and J. Song,Multistep strong first-order electroweak phase transitions in the inverted type-I 2HDM: Parameter space, gravitational waves, and collider phenomenology, Phys. Rev. D112(2025), no. 5 055035, [2506.03260]

  69. [69]

    J. Du, Y. Jiang, and W. Su,Probing the Electroweak Phase Transition in the Flipped Two-Higgs-Doublet Model at the LHC,2605.13939. – 30 –

  70. [70]

    Ghosh, H.-K

    T. Ghosh, H.-K. Guo, T. Han, and H. Liu,Electroweak phase transition with an SU(2) dark sector, JHEP07(2021) 045, [2012.09758]

  71. [71]

    Aoki and H

    M. Aoki and H. Shibuya,Electroweak baryogenesis between broken phases in multi-step phase transition, Phys. Lett. B843(2023) 138041, [2302.11551]

  72. [72]

    Abe and K

    T. Abe and K. Hashino,Gravitational Waves from First-Order Phase Transition in an Electroweakly Interacting Vector Dark Matter Model,PTEP2024(2024), no. 6 063B02, [2302.13510]

  73. [73]

    A. Katz, M. Perelstein, M. J. Ramsey-Musolf, and P. Winslow,Stop-Catalyzed Baryogenesis Beyond the MSSM,Phys. Rev. D92(2015), no. 9 095019, [1509.02934]

  74. [74]

    S. J. Huber and M. G. Schmidt,Electroweak baryogenesis: Concrete in a SUSY model with a gauge singlet,Nucl. Phys. B606(2001) 183–230, [hep-ph/0003122]

  75. [75]

    D. J. H. Chung and A. J. Long,Electroweak Phase Transition in the munuSSM,Phys. Rev. D 81(2010) 123531, [1004.0942]

  76. [76]

    Kozaczuk, S

    J. Kozaczuk, S. Profumo, L. S. Haskins, and C. L. Wainwright,Cosmological Phase Transitions and their Properties in the NMSSM,JHEP01(2015) 144, [1407.4134]

  77. [77]

    Huang, Z

    W. Huang, Z. Kang, J. Shu, P. Wu, and J. M. Yang,New insights in the electroweak phase transition in the NMSSM,Phys. Rev. D91(2015), no. 2 025006, [1405.1152]

  78. [78]

    Borah, P

    P. Borah, P. Ghosh, S. Roy, and A. K. Saha,Electroweak phase transition in a right-handed neutrino superfield extended NMSSM,JHEP08(2023) 029, [2301.05061]

  79. [79]

    Angelescu and P

    A. Angelescu and P. Huang,Multistep Strongly First Order Phase Transitions from New Fermions at the TeV Scale,Phys. Rev. D99(2019), no. 5 055023, [1812.08293]

  80. [80]

    Fu and S

    B. Fu and S. F. King,Gravitational wave signals from leptoquark-induced first-order electroweak phase transitions,JCAP05(2023) 055, [2209.14605]

Showing first 80 references.