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The possibility of primordial black hole direct detection

dc.contributor.authorSobrinho, José Laurindo de Góis Nóbrega
dc.date.accessioned2012-05-04T10:09:37Z
dc.date.available2012-05-04T10:09:37Z
dc.date.issued2011
dc.description.abstractThis thesis explores the possibility of directly detecting blackbody emission from Primordial Black Holes (PBHs). A PBH might form when a cosmological density uctuation with wavenumber k, that was once stretched to scales much larger than the Hubble radius during ination, reenters inside the Hubble radius at some later epoch. By modeling these uctuations with a running{tilt power{law spectrum (n(k) = n0 + a1(k)n1 + a2(k)n2 + a3(k)n3; n0 = 0:951; n1 = 􀀀0:055; n2 and n3 unknown) each pair (n2,n3) gives a di erent n(k) curve with a maximum value (n+) located at some instant (t+). The (n+,t+) parameter space [(1:20,10􀀀23 s) to (2:00,109 s)] has t+ = 10􀀀23 s{109 s and n+ = 1:20{2:00 in order to encompass the formation of PBHs in the mass range 1015 g{1010M (from the ones exploding at present to the most massive known). It was evenly sampled: n+ every 0.02; t+ every order of magnitude. We thus have 41 33 = 1353 di erent cases. However, 820 of these ( 61%) are excluded (because they would provide a PBH population large enough to close the Universe) and we are left with 533 cases for further study. Although only sub{stellar PBHs ( 1M ) are hot enough to be detected at large distances we studied PBHs with 1015 g{1010M and determined how many might have formed and still exist in the Universe. Thus, for each of the 533 (n+,t+) pairs we determined the fraction of the Universe going into PBHs at each epoch ( ), the PBH density parameter (PBH), the PBH number density (nPBH), the total number of PBHs in the Universe (N), and the distance to the nearest one (d). As a rst result, 14% of these (72 cases) give, at least, one PBH within the observable Universe, one{third being sub{stellar and the remaining evenly spliting into stellar, intermediate mass and supermassive. Secondly, we found that the nearest stellar mass PBH might be at 32 pc, while the nearest intermediate mass and supermassive PBHs might be 100 and 1000 times farther, respectively. Finally, for 6% of the cases (four in 72) we might have substellar mass PBHs within 1 pc. One of these cases implies a population of 105 PBHs, with a mass of 1018 g(similar to Halley's comet), within the Oort cloud, which means that the nearest PBH might be as close as 103 AU. Such a PBH could be directly detected with a probability of 10􀀀21 (cf. 10􀀀32 for low{energy neutrinos). We speculate in this possibility.por
dc.description.sponsorshipPedro Manuel Edmond Reis da Silva Augustopor
dc.identifier.tid101238398
dc.identifier.urihttp://hdl.handle.net/10400.13/235
dc.language.isoengpor
dc.peerreviewedyespor
dc.publisherUniversidade da Madeirapor
dc.subjectBlack hole physicspor
dc.subjectEarly universepor
dc.subjectCosmological parameterspor
dc.subjectOort cloudpor
dc.subjectDark matterpor
dc.subjectGalaxy: halopor
dc.subjectMathematics, speciality of Mathematical-Physicspor
dc.subject.por
dc.subjectFaculdade de Ciências Exatas e da Engenharia
dc.titleThe possibility of primordial black hole direct detectionpor
dc.typedoctoral thesis
dspace.entity.typePublication
person.familyNameSobrinho
person.givenNameJosé
person.identifier.ciencia-id2B12-6400-7A5B
person.identifier.orcid0000-0002-9926-2670
person.identifier.scopus-author-id56226247900
rcaap.rightsopenAccesspor
rcaap.typedoctoralThesispor
relation.isAuthorOfPublicatione3f251eb-751b-47da-8cb8-fab8091bd783
relation.isAuthorOfPublication.latestForDiscoverye3f251eb-751b-47da-8cb8-fab8091bd783

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