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dc.contributor.authorHertzberg, Mark P.
dc.contributor.authorLi, Yao
dc.contributor.authorSchiappacasse, Enrico D.
dc.date.accessioned2020-09-16T04:33:52Z
dc.date.available2020-09-16T04:33:52Z
dc.date.issued2020
dc.identifier.citationHertzberg, Mark P.; Li, Yao; Schiappacasse, Enrico D. (2020). Merger of dark matter axion clumps and resonant photon emission. Journal of Cosmology and Astroparticle Physics, 2020 (7), 067. DOI: 10.1088/1475-7516/2020/07/067
dc.identifier.otherCONVID_42046586
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/71776
dc.description.abstractA portion of light scalar dark matter, especially axions, may organize into gravitationally bound clumps (stars) and be present in large number in the galaxy today. It is therefore of utmost interest to determine if there are novel observational signatures of this scenario. Work has shown that for moderately large axion-photon couplings, such clumps can undergo parametric resonance into photons, for clumps above a critical mass Mਮc determined precisely by some of us in ref. [1]. In order to obtain a clump above the critical mass in the galaxy today would require mergers. In this work we perform full 3-dimensional simulations of pairs of axion clumps and determine the conditions under which mergers take place through the emission of scalar waves, including analyzing head-on and non-head-on collisions, phase dependence, and relative velocities. Consistent with other work in the literature, we find that the final mass from the merger Mਮfinal≈ 0.7(Mਮ1+Mਮ2) is larger than each of the original clump masses (for Mਮ1∼ Mਮ2). Hence, it is possible for sub-critical mass clumps to merge and become super-critical and therefore undergo parametric resonance into photons. We find that mergers are expected to be kinematically allowed in the galaxy today for high Peccei-Quinn scales, which is strongly suggested by unification ideas, although the collision rate is small. While mergers can happen for axions with lower Peccei-Quinn scales due to statistical fluctuations in relative velocities, as they have a high collision rate. We estimate the collision and merger rates within the Milky Way galaxy today. We find that a merger leads to a flux of energy on earth that can be appreciable and we mention observational search strategies.en
dc.format.mimetypeapplication/pdf
dc.languageeng
dc.publisherInstitute of Physics
dc.relation.ispartofseriesJournal of Cosmology and Astroparticle Physics
dc.rightsIn Copyright
dc.titleMerger of dark matter axion clumps and resonant photon emission
dc.typearticle
dc.identifier.urnURN:NBN:fi:jyu-202009165869
dc.contributor.laitosFysiikan laitosfi
dc.contributor.laitosDepartment of Physicsen
dc.type.urihttp://purl.org/eprint/type/JournalArticle
dc.description.reviewstatuspeerReviewed
dc.relation.issn1475-7516
dc.relation.numberinseries7
dc.relation.volume2020
dc.type.versionacceptedVersion
dc.rights.copyright© 2020 IOP Publishing Ltd and Sissa Medialab
dc.rights.accesslevelembargoedAccessfi
dc.subject.ysoalkeishiukkaset
dc.subject.ysofotonit
dc.subject.ysopimeä aine
dc.subject.ysokosmologia
dc.subject.ysoastrofysiikka
dc.format.contentfulltext
jyx.subject.urihttp://www.yso.fi/onto/yso/p2064
jyx.subject.urihttp://www.yso.fi/onto/yso/p2063
jyx.subject.urihttp://www.yso.fi/onto/yso/p14101
jyx.subject.urihttp://www.yso.fi/onto/yso/p7160
jyx.subject.urihttp://www.yso.fi/onto/yso/p20188
dc.rights.urlhttp://rightsstatements.org/page/InC/1.0/?language=en
dc.relation.doi10.1088/1475-7516/2020/07/067


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