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Author |
Barenboim, G.; Park, W.I. |
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Title |
A full picture of large lepton number asymmetries of the Universe |
Type |
Journal Article |
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Year |
2017 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
04 |
Issue |
4 |
Pages |
048 - 10pp |
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Keywords  |
cosmological neutrinos; cosmology of theories beyond the SM; leptogenesis; physics of the early universe |
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Abstract |
A large lepton number asymmetry of O(0.1-1) at present Universe might not only be allowed but also necessary for consistency among cosmological data. We show that, if a sizeable lepton number asymmetry were produced before the electroweak phase transition, the requirement for not producing too much baryon number asymmetry through sphalerons processes, forces the high scale lepton number asymmetry to be larger than about 30. Therefore a mild entropy release causing O(10-100) suppression of pre-existing particle density should take place, when the background temperature of the Universe is around T = O(10(-2) -10(2)) GeV for a large but experimentally consistent asymmetry to be present today. We also show that such a mild entropy production can be obtained by the late-time decays of the saxion, constraining the parameters of the Peccei-Quinn sector such as the mass and the vacuum expectation value of the saxion field to be m(phi) greater than or similar to O(10) TeV and phi(0) greater than or similar to O(10(14)) GeV, respectively. |
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Address |
[Barenboim, Gabriela] Univ Valencia, CSIC, Dept Fis Teor, C Dr Moliner 50, E-46100 Burjassot, Spain, Email: Gabriela.Barenboim@uv.es; |
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Publisher |
Iop Publishing Ltd |
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Language |
English |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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ISSN |
1475-7516 |
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Expedition |
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Conference |
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Notes |
WOS:000401806200048 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3148 |
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Author |
Archidiacono, M.; Gariazzo, S.; Giunti, C.; Hannestad, S.; Tram, T. |
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Title |
Sterile neutrino self-interactions: H-0 tension and short-baseline anomalies |
Type |
Journal Article |
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Year |
2020 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
12 |
Issue |
12 |
Pages |
029 - 20pp |
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Keywords |
cosmological neutrinos; cosmological parameters from CMBR; particle physics – cosmology connection; physics of the early universe |
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Abstract |
Sterile neutrinos with a mass in the eV range have been invoked as a possible explanation of a variety of short baseline (SBL) neutrino oscillation anomalies. However, if one considers neutrino oscillations between active and sterile neutrinos, such neutrinos would have been fully thermalised in the early universe, and would be therefore in strong conflict with cosmological bounds. In this study we first update cosmological bounds on the mass and energy density of eV-scale sterile neutrinos. We then perform an updated study of a previously proposed model in which the sterile neutrino couples to a new light pseudoscalar degree of freedom. Consistently with previous analyses, we find that the model provides a good fit to all cosmological data and allows the high value of H-0 measured in the local universe to be consistent with measurements of the cosmic microwave background. However, new high l polarisation data constrain the sterile neutrino mass to be less than approximately 1 eV in this scenario. Finally, we combine the cosmological bounds on the pseudoscalar model with a Bayesian inference analysis of SBL data and conclude that only a sterile mass in narrow ranges around 1 eV remains consistent with both cosmology and SBL data. |
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Address |
[Archidiacono, Maria] Univ Milan, Via G Celoria 16, I-20133 Milan, Italy, Email: maria.archidiacono@unimi.it; |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Language |
English |
Summary Language |
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Series Volume |
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ISSN |
1475-7516 |
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Conference |
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Notes |
WOS:000609105900015 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4688 |
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Author |
Auclair, P.; Blanco-Pillado, J.J.; Figueroa, D.G.; Jenkins, A.C.; Lewicki, M.; Sakellariadou, M.; Sanidas, S.; Sousa, L.; Steer, D.A.; Wachter, J.M.; Kuroyanagi, S. |
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Title |
Probing the gravitational wave background from cosmic strings with LISA |
Type |
Journal Article |
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Year |
2020 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
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Volume |
04 |
Issue |
4 |
Pages |
034 - 50pp |
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Keywords |
Cosmic strings; domain walls; monopoles; gravitational waves / sources; physics of the early universe; primordial gravitational waves (theory) |
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Abstract |
Cosmic string networks offer one of the best prospects for detection of cosmological gravitational waves (GWs). The combined incoherent GW emission of a large number of string loops leads to a stochastic GW background (SGWB), which encodes the properties of the string network. In this paper we analyze the ability of the Laser Interferometer Space Antenna (LISA) to measure this background, considering leading models of the string networks. We find that LISA will be able to probe cosmic strings with tensions G μgreater than or similar to O(10(-17)), improving by about 6 orders of magnitude current pulsar timing arrays (PTA) constraints, and potentially 3 orders of magnitude with respect to expected constraints from next generation PTA observatories. We include in our analysis possible modifications of the SGWB spectrum due to different hypotheses regarding cosmic history and the underlying physics of the string network. These include possible modifications in the SGWB spectrum due to changes in the number of relativistic degrees of freedom in the early Universe, the presence of a non-standard equation of state before the onset of radiation domination, or changes to the network dynamics due to a string inter-commutation probability less than unity. In the event of a detection, LISA's frequency band is well-positioned to probe such cosmic events. Our results constitute a thorough exploration of the cosmic string science that will be accessible to LISA. |
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Address |
[Auclair, Pierre; Steer, Daniele A.] Univ Paris, Lab Astroparticule & Cosmol, 10 Rue Alice Domon & Leonie Duquet, Paris 75013, France, Email: daniel.figueroa@cern.ch |
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Corporate Author |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Language |
English |
Summary Language |
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Original Title |
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Series Volume |
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Series Issue |
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ISSN |
1475-7516 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000531476300035 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4393 |
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Author |
Reichardt, C.L.; de Putter, R.; Zahn, O.; Hou, Z. |
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Title |
New limits on early dark energy from the South Pole telescope |
Type |
Journal Article |
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Year |
2012 |
Publication |
Astrophysical Journal Letters |
Abbreviated Journal |
Astrophys. J. Lett. |
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Volume |
749 |
Issue |
1 |
Pages |
L9 - 5pp |
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Keywords |
cosmic background radiation; dark energy; early universe |
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Abstract |
We present new limits on early dark energy (EDE) from the cosmic microwave background (CMB) using data from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite on large angular scales and South Pole Telescope on small angular scales. We find a strong upper limit on the EDE density of Omega(e) < 0.018 at 95% confidence, a factor of three improvement over WMAP data alone. We show that adding lower-redshift probes of the expansion rate to the CMB data improves constraints on the dark energy equation of state, but not the EDE density. We also explain how small-scale CMB temperature anisotropy constrains EDE. |
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Address |
[Reichardt, C. L.; Zahn, O.] Univ Calif Berkeley, Dept Phys, Berkeley Ctr Cosmol Phys, Berkeley, CA 94720 USA, Email: cr@bolo.berkeley.edu |
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Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2041-8205 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000302143100009 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
962 |
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Author |
Giare, W.; Di Valentino, E.; Melchiorri, A.; Mena, O. |
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Title |
New cosmological bounds on hot relics: axions and neutrinos |
Type |
Journal Article |
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Year |
2021 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
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Volume |
505 |
Issue |
2 |
Pages |
2703-2711 |
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Keywords |
cosmic background radiation; cosmological parameters; dark matter; early Universe; cosmology: observations |
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Abstract |
Axions, if realized in nature, can be copiously produced in the early universe via thermal processes, contributing to the mass-energy density of thermal hot relics. In light of the most recent cosmological observations, we analyse two different thermal processes within a realistic mixed hot dark matter scenario which includes also massive neutrinos. Considering the axion-gluon thermalization channel, we derive our most constraining bounds on the hot relic masses m(a) < 7.46 eV and Sigma m(nu) < 0.114 eV both at 95 percent CL; while studying the axion-pion scattering, without assuming any specific model for the axion-pion interactions, and remaining in the range of validity of the chiral perturbation theory, our most constraining bounds are improved to m(a) < 0.91 eV and Sigma m(nu) < 0.105 eV, both at 95 percent CL. Interestingly, in both cases, the total neutrino mass lies very close to the inverted neutrino mass ordering prediction. If future terrestrial double beta decay and/or long-baseline neutrino experiments find that the nature mass ordering is the inverted one, this could rule out a wide region in the currently allowed thermal axion window. Our results therefore, strongly support multi messenger searches of axions and neutrino properties, together with joint analyses of their expected sensitivities. |
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Address |
[Giare, William; Melchiorri, Alessandro] Univ Roma La Sapienza, Phys Dept, Ple Aldo Moro 2, I-00185 Rome, Italy, Email: william.giare@gmail.com |
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Thesis |
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Publisher |
Oxford Univ Press |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0035-8711 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000672803400085 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4912 |
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