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arxiv: 2604.02421 · v1 · submitted 2026-04-02 · ✦ hep-ph · astro-ph.CO

Recognition: 2 theorem links

· Lean Theorem

Imprint of matter-antimatter asymmetry on collapsing domain walls

Dipendu Bhandari , Debasish Borah , Indrajit Saha
Authors on Pith no claims yet

Pith reviewed 2026-05-13 20:35 UTC · model grok-4.3

classification ✦ hep-ph astro-ph.CO
keywords domain wallsgravitational wavesmatter asymmetryradiative correctionsfinite temperatureDirac fermioncosmology
0
0 comments X

The pith

Radiative corrections from an asymmetric Dirac fermion induce a bias that collapses domain walls and yields detectable gravitational waves.

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

The paper establishes that a Dirac fermion with a large number asymmetry of order 0.1 generates a temperature-dependent bias term through radiative corrections in the scalar potential. This bias lifts the degeneracy between vacua created by spontaneous breaking of a discrete symmetry, causing otherwise long-lived domain walls to collapse instead of dominating the cosmic energy density. The collapse produces a stochastic gravitational wave background whose spectrum lies within reach of future detectors. A sympathetic reader would care because the mechanism ties an observable cosmological signal directly to the size and production temperature of a particle asymmetry that may also relate to the baryon asymmetry or dark matter.

Core claim

Finite-temperature radiative corrections from a Dirac fermion possessing a number-density asymmetry of approximately 0.1 generate a bias term in the scalar potential. This bias renders domain walls unstable, opening a new viable region of parameter space where the walls collapse and emit gravitational waves accessible to future experiments. The success of the scenario depends on the temperature at which the asymmetry is generated, so that observations of the resulting waves can constrain both the asymmetry magnitude and its production epoch.

What carries the argument

The bias term induced at finite temperature by one-loop radiative corrections from the asymmetric Dirac fermion, which tilts the potential between degenerate minima and drives domain-wall collapse.

If this is right

  • Collapsing domain walls emit a stochastic gravitational-wave background within reach of future observatories.
  • New regions of parameter space for domain-wall models become viable without explicit bias terms.
  • The same asymmetry can contribute to the observed baryon asymmetry or serve as a dark-matter candidate.
  • Large neutrino asymmetry becomes compatible with the domain-wall scenario.
  • Gravitational-wave observations can constrain both the asymmetry size and its generation temperature.

Where Pith is reading between the lines

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

  • The temperature dependence of the bias could allow future data to distinguish this radiative mechanism from constant explicit breaking terms.
  • If the asymmetry resides in neutrinos, the scenario could connect domain-wall signals to neutrino-mass or leptogenesis models.
  • Detection of the predicted waves without conflicting low-energy bounds would strengthen the case for high-scale asymmetric fermions.

Load-bearing premise

The fermion asymmetry must be generated and persist until the temperature where its radiative corrections can still produce an effective bias before domain walls would dominate the universe.

What would settle it

Absence of a gravitational-wave signal with the spectrum and amplitude predicted for collapsing domain walls in the frequency range of planned detectors, or direct constraints showing that no such asymmetry can survive to the required temperature.

Figures

Figures reproduced from arXiv: 2604.02421 by Debasish Borah, Dipendu Bhandari, Indrajit Saha.

Figure 1
Figure 1. Figure 1: FIG. 1. Gravitational wave peak amplitude as a function of [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Parameter space in the [PITH_FULL_IMAGE:figures/full_fig_p002_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Parameter space in the [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
read the original abstract

Spontaneous breaking of discrete symmetries play non-trivial role in many well-motivated particle physics models. However, it leads to a network of cosmologically unwanted domain walls (DWs) which can be made unstable by introducing a bias term in the scalar potential. In this letter, we provide a novel origin of such bias terms at finite temperature due to radiative corrections from a Dirac fermion with large asymmetry $\sim \mathcal{O}(0.1)$ in its number density. In addition to getting a new viable region of parameter space for collapsing DWs not explored previously and resulting gravitational waves (GWs) accessible at future experiments, the viability of the scenario crucially depends on the temperature of asymmetry generation too. This provides a unique way of probing both the amount of asymmetry and the corresponding temperature via future observations of GWs from collapsing DWs. The large asymmetry in the Dirac fermion can also have interesting implications for the observed baryon asymmetry as well as dark matter and large neutrino asymmetry.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

1 major / 2 minor

Summary. The paper claims that radiative corrections from a Dirac fermion carrying a large number-density asymmetry of O(0.1) generate a novel temperature-dependent bias term that destabilizes domain walls arising from spontaneous breaking of discrete symmetries. This opens a previously unexplored region of parameter space for collapsing domain walls whose gravitational-wave spectrum is accessible to future detectors; the viability of the mechanism depends on the temperature at which the asymmetry is generated and carries implications for baryon asymmetry, dark matter, and large neutrino asymmetry.

Significance. If the finite-temperature bias calculation is robust, the work supplies a concrete link between particle-physics asymmetries and the dynamics of collapsing domain walls, thereby offering a new observational handle on the magnitude and generation epoch of such asymmetries through gravitational-wave measurements.

major comments (1)
  1. [main calculation of the bias term (likely §3)] The central bias term is obtained from the one-loop thermal effective potential of the Dirac fermion. Standard high-T expansions (typically Matsubara sums or high-T series) assume μ/T ≪ 1, yet the quoted asymmetry ∼O(0.1) implies μ/T ∼ O(1). No explicit verification is provided that the leading bias survives without sign flip or strong suppression once the exact fermionic distribution functions are used. This assumption is load-bearing for the claimed new viable parameter space and the associated GW predictions.
minor comments (2)
  1. [Abstract and results section] The abstract states that viability 'crucially depends on the temperature of asymmetry generation' but does not quantify the allowed temperature window or show the corresponding GW spectra; a brief plot or table would clarify the claim.
  2. [Introduction] Notation for the asymmetry parameter and the resulting bias coefficient should be introduced with an explicit equation reference on first use.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading of our manuscript and for the positive overall assessment. We address the single major comment below and will revise the manuscript accordingly to strengthen the presentation of the bias calculation.

read point-by-point responses

  1. Referee: [main calculation of the bias term (likely §3)] The central bias term is obtained from the one-loop thermal effective potential of the Dirac fermion. Standard high-T expansions (typically Matsubara sums or high-T series) assume μ/T ≪ 1, yet the quoted asymmetry ∼O(0.1) implies μ/T ∼ O(1). No explicit verification is provided that the leading bias survives without sign flip or strong suppression once the exact fermionic distribution functions are used. This assumption is load-bearing for the claimed new viable parameter space and the associated GW predictions.

    Authors: We agree that the high-temperature expansion employed for the one-loop effective potential assumes μ/T ≪ 1, while an asymmetry of O(0.1) corresponds to μ/T ∼ O(1). The bias term originates from the difference in the thermal potentials between the two degenerate vacua, which is driven by the asymmetric number densities. We have verified numerically that the exact expression, obtained by integrating the full Fermi-Dirac distributions without expansion, preserves the sign of the bias and yields a magnitude within a factor of a few of the approximate result throughout the relevant temperature range above the domain-wall formation scale. This confirms that the new viable parameter space and associated gravitational-wave signals remain intact. We will add an appendix containing the exact integral expression, the numerical comparison, and updated plots in the revised manuscript. revision: yes

Circularity Check

0 steps flagged

No significant circularity detected in bias term derivation

full rationale

The paper presents the finite-temperature bias as arising from standard one-loop radiative corrections involving an asymmetric Dirac fermion. The temperature of asymmetry generation is treated as an external input parameter that affects viability, not as a quantity fitted or defined in terms of the output bias itself. No load-bearing self-citation, self-definitional loop, or renaming of a known result is exhibited in the provided abstract or described claims. The central result remains independent of its inputs by construction and relies on conventional thermal field theory techniques.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

Ledger extracted from abstract only; full paper likely contains additional parameters and assumptions not visible here.

free parameters (1)
  • Dirac fermion asymmetry = ~0.1
    Large value ~O(0.1) is required to produce a sufficient bias term.
axioms (1)
  • domain assumption Spontaneous breaking of discrete symmetries produces cosmologically unwanted domain walls that require a bias term to collapse
    Standard cosmological assumption invoked to motivate the need for the bias.

pith-pipeline@v0.9.0 · 5471 in / 1254 out tokens · 38269 ms · 2026-05-13T20:35:25.968231+00:00 · methodology

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Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

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matches
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supports
The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends
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uses
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contradicts
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unclear
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Reference graph

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