Kinetic fragmentation of the QCD axion on the lattice
Kinetic misalignment, one of the most compelling scenarios for the non-thermal generation of axion dark matter, is generally accompanied by axion fragmentation, a process in which the energy of the axion condensate is transferred to its perturbations. The dynamics of fragmentation, at least in the c...
| Autores: | , , , |
|---|---|
| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2025 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositório: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:dnet:digitalcsic_::b1a8f93ba87f0edc80e6a3e04c72b002 |
| Acesso em linha: | http://hdl.handle.net/10261/428817 https://www.scopus.com/pages/publications/105015193502?origin=resultslist |
| Access Level: | Acceso aberto |
| Palavra-chave: | axions dark matter simulations |
| id |
ES_c8620299de38f2ffcc3dd307dd2b6be8 |
|---|---|
| oai_identifier_str |
oai:dnet:digitalcsic_::b1a8f93ba87f0edc80e6a3e04c72b002 |
| network_acronym_str |
ES |
| network_name_str |
España |
| repository_id_str |
|
| dc.title.none.fl_str_mv |
Kinetic fragmentation of the QCD axion on the lattice |
| title |
Kinetic fragmentation of the QCD axion on the lattice |
| spellingShingle |
Kinetic fragmentation of the QCD axion on the lattice Fasiello, M. axions dark matter simulations |
| title_short |
Kinetic fragmentation of the QCD axion on the lattice |
| title_full |
Kinetic fragmentation of the QCD axion on the lattice |
| title_fullStr |
Kinetic fragmentation of the QCD axion on the lattice |
| title_full_unstemmed |
Kinetic fragmentation of the QCD axion on the lattice |
| title_sort |
Kinetic fragmentation of the QCD axion on the lattice |
| dc.creator.none.fl_str_mv |
Fasiello, M. Lizarraga, J. Papageorgiou, A. Urio, A. |
| author |
Fasiello, M. |
| author_facet |
Fasiello, M. Lizarraga, J. Papageorgiou, A. Urio, A. |
| author_role |
author |
| author2 |
Lizarraga, J. Papageorgiou, A. Urio, A. |
| author2_role |
author author author |
| dc.contributor.none.fl_str_mv |
Ministerio de Ciencia e Innovación (España) Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72] |
| dc.subject.none.fl_str_mv |
axions dark matter simulations |
| topic |
axions dark matter simulations |
| description |
Kinetic misalignment, one of the most compelling scenarios for the non-thermal generation of axion dark matter, is generally accompanied by axion fragmentation, a process in which the energy of the axion condensate is transferred to its perturbations. The dynamics of fragmentation, at least in the context of dark matter production, have so far been studied semi-analytically using perturbation theory. In this work, we present the first classical lattice simulation of kinetic axion fragmentation in the context of dark matter production, focusing on parameters relevant to the QCD axion. Our findings indicate that the non-perturbative dynamics captured by the lattice lead to a significantly broader spectrum of axion fluctuations, with a sustained transfer of energy to mildly relativistic modes and with smaller occupation numbers compared to the linear approximation. As a consequence, the final dark matter abundance is typically O(1) lower than in the linear approximation, which is itself O(1) lower than the zero-mode-only prediction. This broadening and suppression of the spectrum could have a significant impact on axion mini-halo formation, one of the main experimental handles on kinetic fragmentation. © 2025 The Author(s) |
| publishDate |
2025 |
| dc.date.none.fl_str_mv |
2025 2026 2026 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/article http://purl.org/coar/resource_type/c_6501 Publisher's version info:eu-repo/semantics/publishedVersion |
| format |
article |
| status_str |
publishedVersion |
| dc.identifier.none.fl_str_mv |
http://hdl.handle.net/10261/428817 https://www.scopus.com/pages/publications/105015193502?origin=resultslist |
| url |
http://hdl.handle.net/10261/428817 https://www.scopus.com/pages/publications/105015193502?origin=resultslist |
| dc.language.none.fl_str_mv |
Inglés |
| language_invalid_str_mv |
Inglés |
| dc.relation.none.fl_str_mv |
Journal of Cosmology and Astroparticle Physics https://iopscience.iop.org/article/10.1088/1475-7516/2025/09/019 Sí |
| dc.rights.none.fl_str_mv |
info:eu-repo/semantics/openAccess |
| eu_rights_str_mv |
openAccess |
| dc.publisher.none.fl_str_mv |
IOP Publishing |
| publisher.none.fl_str_mv |
IOP Publishing |
| dc.source.none.fl_str_mv |
reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC instname:Consejo Superior de Investigaciones Científicas (CSIC) |
| instname_str |
Consejo Superior de Investigaciones Científicas (CSIC) |
| reponame_str |
DIGITAL.CSIC. Repositorio Institucional del CSIC |
| collection |
DIGITAL.CSIC. Repositorio Institucional del CSIC |
| repository.name.fl_str_mv |
|
| repository.mail.fl_str_mv |
|
| _version_ |
1869419280691363840 |
| spelling |
Kinetic fragmentation of the QCD axion on the latticeFasiello, M.Lizarraga, J.Papageorgiou, A.Urio, A.axionsdark matter simulationsKinetic misalignment, one of the most compelling scenarios for the non-thermal generation of axion dark matter, is generally accompanied by axion fragmentation, a process in which the energy of the axion condensate is transferred to its perturbations. The dynamics of fragmentation, at least in the context of dark matter production, have so far been studied semi-analytically using perturbation theory. In this work, we present the first classical lattice simulation of kinetic axion fragmentation in the context of dark matter production, focusing on parameters relevant to the QCD axion. Our findings indicate that the non-perturbative dynamics captured by the lattice lead to a significantly broader spectrum of axion fluctuations, with a sustained transfer of energy to mildly relativistic modes and with smaller occupation numbers compared to the linear approximation. As a consequence, the final dark matter abundance is typically O(1) lower than in the linear approximation, which is itself O(1) lower than the zero-mode-only prediction. This broadening and suppression of the spectrum could have a significant impact on axion mini-halo formation, one of the main experimental handles on kinetic fragmentation. © 2025 The Author(s)MF and AP acknowledge the “Consolidación Investigadora” grant CNS2022-135590. The work of MF and AP is partially supported by the Spanish Research Agency (Agencia Estatal de Investigación) through the Grant IFT Centro de Excelencia Severo Ochoa No. CEX2020-001007-S, funded by MCIN/AEI/10.13039/501100011033. MF acknowledges support from the “Ramón y Cajal” grant RYC2021-033786-I. JL and AU acknowledge the – 20 – JCAP09(2025)019support from Eusko Jaurlaritza (IT1628-22) and the PID2021-123703NB-C21 grant funded by MCIN/AEI/10.13039/501100011033/ and by ERDF; “A way of making Europe”. In particular AU gratefully acknowledges the support from the University of the Basque Country grant PIF20/151. The simulations of this work have been possible thanks to the computing infrastructure of the Solaris cluster at the University of the Basque Country, UPV/EHU and the Hyperion cluster from the DIPC Supercomputing Center. Part of this work was carried out during the 2025 workshop “The Dawn of Gravitational Wave Cosmology”, supported by the Fundación Ramón Areces and hosted by the “Centro de Ciencias de Benasque Pedro Pascual”. We thank both the CCBPP and the Fundación Ramón Areces for providing a stimulating and highly productive research environment. A Initial conditions for the perturbations The initial conditions of the axion perturbations in this scenario are highly non-trivial. During radiation domination, if the axion zero-mode features a large velocity, the superhorizon perturbations of the axion are affected by the superhorizon density fluctuations. This was initially pointed out in [ 115, 116 ] and has been used explicitly in the context of kinetic fragmentation in [ 81 ]. We defer the reader to these references for the complete derivation. Instead we will only outline the steps in this appendix for completeness. Defining the perturbed metric as ds2 = a(τ )2 { − [1 + 2Ψ(τ, ⃗x )] dτ 2 + [1 + 2Φ(τ, ⃗x )] δij dxidxj } . (A.1) We assume the absence of anisotropic stress Ψ = −Φ. Under these conventions, the primordial density perturbations couple to the speed of the axion zero mode and source the axion perturbations at superhorizon scales. At early times when the mass of the axion can be neglected the equation of motion of the perturbations takes the form θ′′ k + 2 a(τ )′ a(τ ) θ′ k + k2θk = −4Φ′ kΘ′ . (A.2) It is useful to rewrite this equation in terms of variable x ≡ kτ /√3 d2θkPeer reviewedIOP PublishingMinisterio de Ciencia e Innovación (España)Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]202620262025info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Publisher's versioninfo:eu-repo/semantics/publishedVersionhttp://hdl.handle.net/10261/428817https://www.scopus.com/pages/publications/105015193502?origin=resultslistreponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)InglésJournal of Cosmology and Astroparticle Physicshttps://iopscience.iop.org/article/10.1088/1475-7516/2025/09/019Síinfo:eu-repo/semantics/openAccessoai:dnet:digitalcsic_::b1a8f93ba87f0edc80e6a3e04c72b0022026-05-22T06:33:51Z |
| score |
15,812429 |