Pith. sign in

REVIEW 4 minor 2 cited by

Caustic formation in DBI models: Wave propagation on planar domain walls

T0 review · 0 major / 4 minor · reviewed 2026-07-13 · grok-4.5

Pith's one-line read DBI waves on planar domain walls stay caustic-free while hyperbolic; only loss of hyperbolicity produces cusps.

desk verdict Clean analytic proof that hyperbolic DBI stays caustic-free for generic waves, including under the three deformations that matter for domain walls. read the letter →

arxiv 2604.08142 v2 pith:T7FPKUZH submitted 2026-04-09 hep-th astro-ph.COgr-qchep-ph

classification hep-thastro-ph.COgr-qchep-ph PACS 11.27.+d98.80.Cq04.20.Jb
keywords Dirac-Born-InfelddomainwallscausticscharacteristicshyperbolicitycuspsNambu-Gotocosmology
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

Domain walls in cosmology are often modeled by the scalar Dirac-Born-Infeld (DBI) action. Caustics on those walls could source intense particle emission and help the network reach scaling. This paper asks whether generic waves on planar walls can form caustics while the equation remains hyperbolic. In two-dimensional flat space the same-family characteristic curves stay parallel for all time, so they never cross if the initial data are smooth. Beyond that idealized setting—spherical waves, an expanding universe, or the linear deformation that lets walls annihilate—the characteristics are no longer globally parallel. Nevertheless the authors prove that caustics still cannot form while hyperbolicity holds, because the second mixed derivative of time forces any vanishing of a first derivative to propagate everywhere, contradicting smooth initial conditions. The only remaining singularities are therefore non-hyperbolic cusps whose formation is strongly altered by the realistic characteristic geometry.

What carries the argument

The method of characteristics for the first-order system that governs the field derivatives τ and χ. In pure two-dimensional DBI the phase velocities ξ± depend only on their own characteristic parameter, forcing ∂²t/∂ω₊∂ω₋ = 0 and thereby forbidding caustics. With a source Q independent of second derivatives the same mixed derivative becomes proportional to (∂t/∂ω₊)(∂t/∂ω₋), turning the evolution of each first derivative into a linear ODE whose uniqueness still precludes caustics.

What would settle it

A numerical evolution of the full DBI equation (or of its spherical/expanding/linearly-deformed versions) that begins with smooth, strictly hyperbolic initial data and develops a finite-time caustic while the sound speed remains positive would falsify the claim.

Watch

Extended reading notes

Core claim

In the hyperbolic regime, scalar DBI remains free of caustics for generic waves both in two-dimensional Minkowski space (where same-family characteristics remain parallel) and under the physically relevant source terms that appear for spherical waves, cosmic expansion, and linear wall-annihilation deformations; the only caustics that can form are those associated with loss of hyperbolicity and they possess a cusp profile.

Load-bearing premise

The extra source term that appears once the problem leaves pure two-dimensional flat space is assumed not to depend on second derivatives of the wall field; that assumption turns the evolution equation into a linear ODE whose uniqueness blocks caustics.

Editorial extensions

If this is right

  • Particle emission from planar domain walls is expected only where hyperbolicity is lost, i.e., at cusps where the sound speed vanishes.
  • Realistic characteristic geometry (expansion, spherical waves, annihilation term) can either create or suppress cusps relative to the flat two-dimensional idealization, so conclusions drawn from the simplified model need re-examination.
  • The same uniqueness argument extends immediately to any curved two-dimensional background that produces a source independent of second derivatives.
  • Melting domain walls, which live effectively in Minkowski space and need no annihilation term, should exhibit a different cusp pattern from constant-tension walls.

Reading between the lines

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

  • Because the proof is limited to spherical symmetry in D>2, a fully three-dimensional non-spherical wave packet could still form hyperbolic caustics and would be the natural next numerical target.
  • If cusps are the dominant particle-production channel, the abundance of closed wall loops or the gravitational-wave spectrum from domain-wall networks should correlate with the rate at which sound speed reaches zero.
  • The linear uniqueness argument may fail for higher-order corrections that reintroduce second-derivative dependence into the source, offering a concrete way to test the robustness of the no-caustic statement.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

0 major / 4 minor

Summary. The paper studies generic wave propagation on thin planar domain walls in the scalar DBI model, with emphasis on caustic formation. In 2D flat spacetime it proves that, for smooth initial data in the hyperbolic regime, same-family characteristics remain parallel (ξ_{+} = ξ_{+}(ω_{+}), ξ_{-} = ξ_{-}(ω_{-})) even though they are not straight lines; consequently ∂^{2}t/∂ω_{+}∂ω_{-} = 0 and ∂t/∂ω_{+} cannot vanish at later times, so no caustics form. Beyond this setting—spherical waves in D > 2, an expanding FLRW background, and the minimal linear deformation of DBI that solves the domain-wall problem—the characteristics cease to be globally parallel, yet the paper shows that the mixed derivative still forces a linear first-order ODE for ∂t/∂ω_{+} along each characteristic; uniqueness then precludes caustics from smooth data. The only remaining singularities are therefore non-hyperbolic cusps (c_s = 0), whose formation is shown to be sensitive to the non-trivial characteristic structure uncovered in the deformed cases.

Significance. The result supplies a parameter-free analytic demonstration that hyperbolic DBI is caustic-free for generic waves under the deformations most relevant to cosmology. This sharpens the physical picture of particle emission from domain walls: emission is expected only when hyperbolicity is lost and cusps form. The exact solvability of 2D DBI, the transparent use of Riemann invariants and characteristic coordinates, and the explicit comparison of cusp formation with and without expansion or a linear term constitute clear technical advances over earlier simple-wave analyses. The work therefore strengthens the theoretical foundation for both domain-wall network simulations and the broader study of caustics in P(X) theories.

minor comments (4)
  1. Abstract and Sec. 1: a few typographical slips remain (“waveson”, “a row of physically relevant situations”). A light copy-edit would remove them.
  2. Figs. 1–4: the captions state the functional forms of the Riemann invariants and the value of ϵ or H, but do not record the numerical integrator or the precise initial data for ϕ itself. Adding a short sentence or an appendix note would make the illustrations fully reproducible.
  3. Eq. (56) and the paragraph that follows: the assumption that Q is independent of first derivatives of τ and χ is verified case-by-case, yet a single clarifying sentence early in Sec. 6 would help the reader see that the linear ODE structure is not accidental.
  4. Appendix A: the conformal-gauge expansion (74)–(82) is useful; a brief remark on how the same cusp profile is recovered from the static-gauge Euler equation (64) would tighten the cross-check.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the no-caustic theorems are self-contained analytic derivations from the DBI Lagrangian and the method of characteristics.

full rationale

The paper derives the characteristic slopes ξ± from the DBI sound speed (Eqs. 21–31), obtains the key structural property ξ±=ξ±(ω±) that forces ∂^{2}t/∂ω_{+}∂ω_{-}=0 (Eqs. 34–43), and proves that ∂t/∂ω± cannot vanish later if it is non-zero on smooth initial data (Sec. 5). The same logic is extended to the deformed equation (53) by showing that the source Q produces a linear first-order ODE (57) whose uniqueness again forbids a zero of ∂t/∂ω_{+} once smooth initial data are imposed (Sec. 6). All three concrete sources Q (spherical, Hubble, linear annihilating term) are computed explicitly from the action and do not depend on second derivatives of φ. Self-citations (Babichev 2016, Mukohyama et al. 2016, etc.) supply only the background method of characteristics and earlier simple-wave results; they are not used as uniqueness theorems that force the present generic-wave statements. No parameters are fitted, no empirical pattern is renamed, and the open status of non-spherical D>2 is stated honestly. The derivation chain is therefore independent of its own conclusions.

Assumptions & free parameters 0 free parameters · 4 assumptions · 0 invented entities

The paper works entirely within classical scalar field theory and the method of characteristics. No free parameters are fitted; the only modeling choices are the thin-wall limit, the static gauge, and the assumption that the source Q does not depend on second derivatives of the field. No new particles or forces are postulated.

assumptions (4)
  • domain assumption Thin-wall (Nambu–Goto) limit is an accurate effective description of domain walls when the wall width is much smaller than the curvature radius and Hubble scale.
    Invoked in Sec. 2 to replace the microscopic Z_{2} scalar by the DBI action; standard but not derived here.
  • domain assumption Initial data for the DBI field are smooth (finite first and second derivatives).
    Used throughout Secs. 5–6 to exclude pre-existing caustics; stated explicitly as the starting point of the no-caustic proofs.
  • ad hoc to paper The inhomogeneous term Q that appears after including expansion, spherical geometry or a linear potential is independent of the first derivatives of au and heta.
    Stated in Sec. 6; required for the linear ODE uniqueness argument that forbids caustics. Holds for the three concrete cases examined but is not proved in full generality.
  • standard math Hyperbolicity is equivalent to heta_{+} eq heta_{-} (or c_s^{2} > 0).
    Standard classification of second-order PDEs; used to separate the hyperbolic regime from the cusp regime.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Caustic formation in DBI models: Wave propagation on planar domain walls." pith.science (2026). https://pith.science/paper/T7FPKUZH

@misc{pith2026260408142,
  author       = {Pith},
  title        = {Pith review of: Caustic formation in DBI models: Wave propagation on planar domain walls},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/T7FPKUZH}},
  note         = {Machine review of arXiv:2604.08142}
}
abstract

We investigate propagation of generic waves on thin planar domain walls effectively described by the scalar Dirac-Born-Infeld model (DBI). We pay a particular attention to the possibility of caustic formation - the process, which may lead to intensive particle emission by domain walls. It is demonstrated that no singularities arise in DBI in 2D flat spacetime in the hyperbolic case, if one starts from smooth initial conditions. Technically, this happens because the same family characteristics of the relevant partial differential equation remain parallel at all the times, albeit not being straight lines generically. Crucially, characteristic curves cease to be parallel beyond the simplified setup of DBI in 2D flat spacetime. In particular, this is shown to be the case in $D>2$ for spherical waves, in an expanding Universe, and in the case of a minimal deformation of DBI necessary for avoiding the domain wall problem in cosmology. However, we prove that DBI remains caustic free in the hyperbolic case in all these physically relevant situations. This strongly suggests that caustics can form on planar domain walls only due to the loss of hyperbolicity, and they have a cusp profile. We demonstrate, how the non-trivial structure of DBI characteristics beyond the 2D flat spacetime setup uncovered in this work can significantly affect cusp formation.

Figures

Figures reproduced from arXiv: 2604.08142 by the authors.

Figure 1
Figure 1. Characteristic curves in DBI in 2D flat spacetime are demonstrated for a particular [PITH_FULL_IMAGE:figures/full_fig_p011_1.png] view at source ↗
Figure 2
Figure 2. An example of a “perfect” cusp, where all the characteristics from both families [PITH_FULL_IMAGE:figures/full_fig_p017_2.png] view at source ↗
Figure 3
Figure 3. Left panel. Smooth propagation of a wave is demonstrated in the case of DBI in 2D flat spacetime for a particular choice of initial conditions. Middle panel. Cusp formation is shown in the case of DBI extended by the ϵ-term described in the end of Sec. 6, for the same choice of initial conditions as in the left panel. Right panel. The same as in the middle panel with a zoom on the region where the cusp is formed. In… view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: Left panel. Cusp formation is shown in the case of DBI in 2D flat spacetime for a particular choice of initial conditions. Middle panel. The same as in the left panel but with a zoom on the cusp region. Right panel. Wave propagation is demonstrated in the case of DBI f…

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 2 Pith papers

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

  1. Cuspidal Singularities in Collapsing Domain Walls

    hep-th 2026-05 conditional novelty 7.0 of 10

    Collapsing domain walls generically form cuspidal edge and vertex singularities captured by Nambu-Goto and eikonal approximations and reproduced in field theory simulations.

  2. Domain walls through different cosmologies

    astro-ph.CO 2026-07 accept novelty 6.5 of 10

    Domain-wall network area scales as S ≈ 2ξV/τ with ξ≈1.2 across cosmologies from dust to near-Minkowski, so the particle horizon—not H⁻¹—sets the correlation length and GW peak.

Reference graph

Works this paper leans on

61 extracted references · 26 linked inside Pith · cited by 2 Pith papers

  1. [1]

    Yu. A. Kravtsov, Yu. I. Orlov,Caustics, Catastrophes and Wave Fields, Springer-Verlag Berlin Heidelberg 1993

  2. [2]

    Y. B. Zeldovich,Gravitational instability: An Approximate theory for large density perturbations, Astron. Astrophys.5(1970), 84-89

  3. [3]

    I., Shandarin S

    Arnold V. I., Shandarin S. F., Zeldovich Ia. B.,The large scale structure of the universe I. General properties. One-and two-dimensional models, 1982, Geophys. and Astrophys. Fluid Dynamics, 20, no. 1-2, 111

  4. [4]

    Born and L

    M. Born and L. Infeld,Foundations of the new field theory, Proc. Roy. Soc. Lond. A 144(1934) no.852, 425-451

  5. [5]

    P. A. M. Dirac,An Extensible model of the electron, Proc. Roy. Soc. Lond. A268(1962), 57-67

  6. [6]

    Barbashov and N

    B. Barbashov and N. Chernikov,Solution and Quantization of a Nonlinear Two- dimensional Model for a Born-Infeld Type Field, Sov. Phys. JETP23(1966) no.5, 861-868

  7. [7]

    B. M. Barbashov and N. A. Chernikov,Solution of the Two Plane Wave Scattering Problem in a Nonlinear Scalar Field Theory of the Born-Infeld Type, Sov. Phys. JETP 24(1967) no.2, 437-442

  8. [8]

    A. A. Tseytlin,Born-Infeld action, supersymmetry and string theory, [arXiv:hep- th/9908105 [hep-th]]

Show all 61 references
  1. [9]

    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), 3-11 SLAC-TRANS-0165. 27

  2. [10]

    Vilenkin and E

    A. Vilenkin and E. P. S. Shellard,Cosmic Strings and Other Topological Defects, Cam- bridge University Press, 2000

  3. [11]

    Vachaspati,Kinks and Domain Walls : An Introduction to Classical and Quantum Solitons, Oxford University Press, 2007

    T. Vachaspati,Kinks and Domain Walls : An Introduction to Classical and Quantum Solitons, Oxford University Press, 2007

  4. [12]

    A. V. Frolov, L. Kofman and A. A. Starobinsky,Prospects and problems of tachyon matter cosmology, Phys. Lett. B545(2002), 8-16; [arXiv:hep-th/0204187 [hep-th]]

  5. [13]

    Alishahiha, E

    M. Alishahiha, E. Silverstein and D. Tong,DBI in the sky, Phys. Rev. D70(2004), 123505; [arXiv:hep-th/0404084 [hep-th]]

  6. [14]

    W. H. Press, B. S. Ryden and D. N. Spergel,Dynamical Evolution of Domain Walls in an Expanding Universe, Astrophys. J.347(1989), 590-604

  7. [15]

    Hiramatsu, M

    T. Hiramatsu, M. Kawasaki and K. Saikawa,On the estimation of gravitational wave spectrum from cosmic domain walls, JCAP02(2014), 031; [arXiv:1309.5001 [astro- ph.CO]]

  8. [16]

    Dankovsky, S

    I. Dankovsky, S. Ramazanov, E. Babichev, D. Gorbunov and A. Vikman,Cosmic do- main walls on a lattice: Illusive effects of initial conditions, Phys. Rev. D112(2025) no.12, 123521; [arXiv:2509.25367 [hep-ph]]

  9. [17]

    Blasi, A

    S. Blasi, A. Mariotti, A. Rase and M. Vanvlasselaer,Domain walls in the scaling regime: Equal Time Correlator and Gravitational Waves, [arXiv:2511.16649 [hep-ph]]

  10. [18]

    Dankovsky, E

    I. Dankovsky, E. Babichev, D. Gorbunov, S. Ramazanov and A. Vikman,Revisiting evolution of domain walls and their gravitational radiation with CosmoLattice, JCAP 09(2024), 047; [arXiv:2406.17053 [astro-ph.CO]]

  11. [19]

    T. W. B. Kibble,Topology of Cosmic Domains and Strings, J. Phys. A9(1976), 1387- 1398

  12. [20]

    Vachaspati and A

    T. Vachaspati and A. Vilenkin,Gravitational Radiation from Cosmic Strings, Phys. Rev. D31(1985), 3052

  13. [21]

    Vilenkin and T

    A. Vilenkin and T. Vachaspati,Radiation of Goldstone Bosons From Cosmic Strings, Phys. Rev. D35(1987), 1138

  14. [22]

    J. J. Blanco-Pillado and K. D. Olum,Stochastic gravitational wave background from smoothed cosmic string loops, Phys. Rev. D96(2017) no.10, 104046; [arXiv:1709.02693 [astro-ph.CO]]. 28

  15. [23]

    Baeza-Ballesteros, E

    J. Baeza-Ballesteros, E. J. Copeland, D. G. Figueroa and J. Lizarraga,Particle and gravitational wave emission by local string loops: Lattice calculation, Phys. Rev. D112 (2025) no.4, 4; [arXiv:2408.02364 [astro-ph.CO]]

  16. [24]

    G. N. Felder, L. Kofman and A. Starobinsky,Caustics in tachyon matter and other Born-Infeld scalars, JHEP09(2002), 026; [arXiv:hep-th/0208019 [hep-th]]

  17. [25]

    Eggers and J

    J. Eggers and J. Hoppe,Singularity formation for time-like extremal hypersurfaces, Phys. Lett. B680(2009), 274-278

  18. [26]

    M. J. Eggers, J. Hoppe, M. Hynek, N. Suramlishvili,Singularities of relativistic mem- branes, Geometric Flows12015 17-33

  19. [27]

    J. J. Blanco-Pillado, D. Jim´ enez-Aguilar and O. Pujol` as,From cusps to swallowtails: Domain wall singularities in 2+1 dimensions, Phys. Rev. D112(2025) no.12, 123536; [arXiv:2509.19457 [hep-th]]

  20. [28]

    Babichev,Formation of caustics in k-essence and Horndeski theory, JHEP04(2016), 129; [arXiv:1602.00735 [hep-th]]

    E. Babichev,Formation of caustics in k-essence and Horndeski theory, JHEP04(2016), 129; [arXiv:1602.00735 [hep-th]]

  21. [29]

    Mukohyama, R

    S. Mukohyama, R. Namba and Y. Watanabe,Is the DBI scalar field as fragile as other k-essence fields?, Phys. Rev. D94(2016) no.2, 023514; [arXiv:1605.06418 [hep-th]]

  22. [30]

    Deser, J

    S. Deser, J. G. McCarthy and O. Sarioglu,’Good propagation’ constraints on dual invari- ant actions in electrodynamics and on massless fields, Class. Quant. Grav.16(1999), 841-847; [arXiv:hep-th/9809153 [hep-th]]

  23. [31]

    Boillat,Nonlinear electrodynamics - Lagrangians and equations of motion, J

    G. Boillat,Nonlinear electrodynamics - Lagrangians and equations of motion, J. Math. Phys.11(1970) no.3, 941-951

  24. [32]

    D. I. Blokhintsev and V. V. Orlov, Zh. Eksp. Teor. Fiz.25(1953) no.5, 513-526

  25. [33]

    Tanahashi and S

    N. Tanahashi and S. Ohashi,Wave propagation and shock formation in the most general scalar–tensor theories, Class. Quant. Grav.34(2017) no.21, 215003; [arXiv:1704.02757 [hep-th]]

  26. [34]

    Gregory, D

    R. Gregory, D. Haws and D. Garfinkle,The Dynamics of Domain Walls and Strings, Phys. Rev. D42(1990), 343-348

  27. [35]

    Bonjour, C

    F. Bonjour, C. Charmousis and R. Gregory,The Dynamics of curved gravitating walls, Phys. Rev. D62(2000), 083504; [arXiv:gr-qc/0002063 [gr-qc]]. 29

  28. [36]

    J. J. Blanco-Pillado, A. Garc´ ıa Mart´ ın-Caro, D. Jim´ enez-Aguilar and J. M. Queiruga, Effective actions for domain wall dynamics, Phys. Rev. D111(2025) no.5, 056007; [arXiv:2411.13521 [hep-th]]

  29. [37]

    Courant and K

    R. Courant and K. O. Friedrichs,Supersonic Flow and Shock Waves, Interscience Pub- lishers Inc., New York, 1948

  30. [38]

    Courant and D

    R. Courant and D. Hilbert,Methods of Mathematical Physics: Volume II: Partial Dif- ferential Equations, Interscience Publishers (Wiley), New York, 1962

  31. [39]

    V. S. Vladimirov,Equations of mathematical physics, MIR, 1984

  32. [40]

    Garriga and V

    J. Garriga and V. F. Mukhanov,Perturbations in k-inflation, Phys. Lett. B458(1999), 219-225; [arXiv:hep-th/9904176 [hep-th]]

  33. [41]

    Majda,Compressible Fluid Flow and Systems of Conservation Laws in Several Space Variables; Springer New York, NY

    A. Majda,Compressible Fluid Flow and Systems of Conservation Laws in Several Space Variables; Springer New York, NY

  34. [42]

    Afshordi, D

    N. Afshordi, D. J. H. Chung and G. Geshnizjani, Phys. Rev. D75(2007), 083513; [arXiv:hep-th/0609150 [hep-th]]

  35. [43]

    Pasmatsiou,Caustic Formation upon Shift Symmetry Breaking, Phys

    K. Pasmatsiou,Caustic Formation upon Shift Symmetry Breaking, Phys. Rev. D97 (2018) no.3, 036008; [arXiv:1712.02888 [hep-th]]

  36. [44]

    P. D. Lax,Development of singularities of solutions of nonlinear hyperbolic partial dif- ferential equations, Journal of Mathematical Physics5(5) (1964), 611–613

  37. [45]

    P. D. Lax,Hyperbolic systems of conservation laws and the mathematical theory of shock waves, SIAM, 1973

  38. [46]

    P. D. Lax,XII. The Initial Value Problem for Nonlinear Hyperbolic Equations in Two Independent Variables, in Contributions to the Theory of Partial Differential Equations (AM-33), Princeton University Press, 1955, pp. 211–230

  39. [47]

    Babichev,Emergence of ghosts in Horndeski theory,JHEP07(2020), 038; [arXiv:2001.11784 [hep-th]]

    E. Babichev,Emergence of ghosts in Horndeski theory,JHEP07(2020), 038; [arXiv:2001.11784 [hep-th]]

  40. [48]

    de Rham and H

    C. de Rham and H. Motohashi,Caustics for Spherical Waves, Phys. Rev. D95(2017) no.6, 064008; [arXiv:1611.05038 [hep-th]]

  41. [49]

    Babichev and S

    E. Babichev and S. Ramazanov,Caustic free completion of pressureless perfect fluid and k-essence, JHEP08(2017), 040; [arXiv:1704.03367 [hep-th]]. 30

  42. [50]

    J. J. Blanco-Pillado, D. Jim´ enez-Aguilar, J. M. Queiruga and J. Urrestilla,The dynam- ics of domain wall strings, JCAP05(2023), 011; [arXiv:2209.12945 [hep-th]]

  43. [51]

    L. M. Widrow,Dynamics of Thick Domain Walls, Phys. Rev. D40(1989), 1002

  44. [52]

    Ramazanov, E

    S. Ramazanov, E. Babichev, D. Gorbunov and A. Vikman,Beyond freeze-in: Dark matter via inverse phase transition and gravitational wave signal,Phys. Rev. D105 (2022) no.6, 063530; [arXiv:2104.13722 [hep-ph]]

  45. [53]

    Babichev, D

    E. Babichev, D. Gorbunov, S. Ramazanov and A. Vikman,Gravitational shine of dark domain walls, JCAP04(2022) no.04, 028; [arXiv:2112.12608 [hep-ph]]

  46. [54]

    Dankovsky, S

    I. Dankovsky, S. Ramazanov, E. Babichev, D. Gorbunov and A. Vikman,Numerical analysis of melting domain walls and their gravitational waves, JCAP02(2025), 064; [arXiv:2410.21971 [hep-ph]]

  47. [55]

    Babichev, S

    E. Babichev, S. Ramazanov and A. Vikman,RecoveringP(X)from a canonical complex field,JCAP11(2018), 023; [arXiv:1807.10281 [gr-qc]]

  48. [56]

    Israel,Singular hypersurfaces and thin shells in general relativity, Nuovo Cim

    W. Israel,Singular hypersurfaces and thin shells in general relativity, Nuovo Cim. B 44S10(1966), 1 [Erratum: Nuovo Cim.B 48, 463 (1967)]

  49. [57]

    V. A. Berezin, V. A. Kuzmin and I. I. Tkachev,Dynamics of Bubbles in General Rela- tivity, Phys. Rev. D36(1987), 2919

  50. [58]

    Deng and A

    H. Deng and A. Vilenkin,Primordial black hole formation by vacuum bubbles, JCAP 12(2017), 044; [arXiv:1710.02865 [gr-qc]]

  51. [59]

    Deng,Primordial black hole formation by vacuum bubbles

    H. Deng,Primordial black hole formation by vacuum bubbles. Part II, JCAP09(2020), 023; [arXiv:2006.11907 [astro-ph.CO]]

  52. [60]

    Poisson,A Relativist’s Toolkit: The Mathematics of Black-Hole Mechanics, Cam- bridge University Press, 2009

    E. Poisson,A Relativist’s Toolkit: The Mathematics of Black-Hole Mechanics, Cam- bridge University Press, 2009

  53. [61]

    Garriga and A

    J. Garriga and A. Vilenkin,Perturbations on domain walls and strings: A Covariant theory, Phys. Rev. D44(1991), 1007-1014. 31

Pith tools

Reviewed July 13, 2026 · model on record in the stance chip above.