Records |
Author |
Boubekeur, L.; Choi, K.Y.; Ruiz de Austri, R.; Vives, O. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
The degenerate gravitino scenario |
Type |
Journal Article |
Year |
2010 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume |
04 |
Issue |
4 |
Pages |
005 - 26pp |
Keywords |
dark matter theory; leptogenesis; supersymmetry and cosmology; cosmology of theories beyond the SM |
Abstract |
In this work, we explore the “degenerate gravitino” scenario where the mass difference between the gravitino and the lightest MSSM particle is much smaller than the gravitino mass itself. In this case, the energy released in the decay of the next to lightest sypersymmetric particle (NLSP) is reduced. Consequently the cosmological and astrophysical constraints on the gravitino abundance, and hence on the reheating temperature, become softer than in the usual case. On the other hand, such small mass splittings generically imply a much longer lifetime for the NLSP. We find that, in the constrained MSSM (CMSSM), for neutralino LSP or NLSP, reheating temperatures compatible with thermal leptogenesis are reached for small splittings of order 10(-2) GeV. While for stau NLSP, temperatures of T-RH similar or equal to 4 x 10(9) GeV can be obtained even for splittings of order of tens of GeVs. This “degenerate gravitino” scenario offers a possible way out to the gravitino problem for thermal leptogenesis in supersymmetric theories. |
Address |
[Boubekeur, Lotfi; Vives, Oscar] Univ Valencia, Dept Fis Teor, E-46100 Burjassot, Spain, Email: lotfi.boubekeur@uv.es |
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Iop Publishing Ltd |
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English |
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ISSN |
1475-7516 |
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Notes |
ISI:000277684600028 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
453 |
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Author |
Pierre Auger Collaboration (Abreu, P. et al); Pastor, S. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory |
Type |
Journal Article |
Year |
2011 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume |
11 |
Issue |
11 |
Pages |
022 |
Keywords |
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Abstract |
We present a comprehensive study of the influence of the geomagnetic field on the energy estimation of extensive air showers with a zenith angle smaller than 60 degrees, detected at the Pierre Auger Observatory. the geomagnetic field induces an azimuthal modulation of the estimated energy of cosmic rays up to the similar to 2% level at large zenith angles. We present a method to account for this modulation of the reconstructed energy. We analyse the effect of the modulation on large scale anisotropy searches in the arrival direction distributions of cosmic rays. At a given energy, the geomagnetic effect is shown to induce a pseudo-dipolar pattern at the percent level in the declination distribution that needs to be accounted for. |
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1475-7516 |
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Notes |
WOS:000298141300022 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
865 |
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Author |
Mosbech, M.R.; Boehm, C.; Hannestad, S.; Mena, O.; Stadler, J.; Wong, Y.Y.Y. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
The full Boltzmann hierarchy for dark matter-massive neutrino interactions |
Type |
Journal Article |
Year |
2021 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume |
03 |
Issue |
3 |
Pages |
066 - 31pp |
Keywords |
cosmological perturbation theory; dark matter theory; neutrino properties; particle physics – cosmology connection |
Abstract |
The impact of dark matter-neutrino interactions on the measurement of the cosmological parameters has been investigated in the past in the context of massless neutrinos exclusively. Here we revisit the role of a neutrino-dark matter coupling in light of ongoing cosmological tensions by implementing the full Boltzmann hierarchy for three massive neutrinos. Our tightest 95% CL upper limit on the strength of the interactions, parameterized via u(chi) = sigma(0)/sigma(Th) (m(chi)/100GeV)(-1), is u(chi) <= 3.34 . 10(-4), arising from a combination of Planck TTTEEE data, Planck lensing data and SDSS BAO data. This upper bound is, as expected, slightly higher than previous results for interacting massless neutrinos, due to the correction factor associated with neutrino masses. We find that these interactions significantly relax the lower bounds on the value of sigma 8 that is inferred in the context of Lambda CDM from the Planck data, leading to agreement within 1-2 sigma with weak lensing estimates of sigma 8, as those from KiDS1000. However, the presence of these interactions barely affects the value of the Hubble constant H-0. |
Address |
[Mosbech, Markus R.; Boehm, Celine] Univ Sydney, Sch Phys, Camperdown, NSW 2006, Australia, Email: mmos6302@uni.sydney.edu.au; |
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Iop Publishing Ltd |
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English |
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ISSN |
1475-7516 |
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Conference |
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Notes |
WOS:000636717400061 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4783 |
Permanent link to this record |
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Author |
Fornengo, N.; Lineros, R.A.; Regis, M.; Taoso, M. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
The isotropic radio background revisited |
Type |
Journal Article |
Year |
2014 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume |
04 |
Issue |
4 |
Pages |
008 - 36pp |
Keywords |
cosmic ray theory; galactic magnetic fields; dark matter theory |
Abstract |
We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky. |
Address |
[Fornengo, Nicolao; Regis, Marco] Univ Turin, Dipartimento Fis Teor, I-10125 Turin, Italy, Email: fornengo@to.infn.it; |
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Iop Publishing Ltd |
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English |
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ISSN |
1475-7516 |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000334496500008 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1772 |
Permanent link to this record |
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Author |
Escudero, M.; Ramirez, H.; Boubekeur, L.; Giusarma, E.; Mena, O. |
Title ![sorted by Title field, ascending order (up)](img/sort_asc.gif) |
The present and future of the most favoured inflationary models after Planck 2015 |
Type |
Journal Article |
Year |
2016 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume |
02 |
Issue |
2 |
Pages |
020 - 21pp |
Keywords |
inflation; cosmological parameters from CMBR; CMBR experiments |
Abstract |
The value of the tensor-to-scalar ratio r in the region allowed by the latest Planck 2015 measurements can be associated to a large variety of inflationary models. We discuss here the potential of future Cosmic Microwave Background cosmological observations in disentangling among the possible theoretical scenarios allowed by our analyses of current Planck temperature and polarization data. Rather than focusing only on r, we focus as well on the running of the primordial power spectrum, alpha(s) and the running thereof, beta(s). If future cosmological measurements, as those from the COrE mission, confirm the current best-fit value for beta(s) greater than or similar to 10(-2) as the preferred one, it will be possible to rule-out the most favoured inflationary models. |
Address |
[Escudero, Miguel; Ramirez, Hector; Boubekeur, Lotfi; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain, Email: miguel.escudero@ific.uv.es; |
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Thesis |
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Publisher |
Iop Publishing Ltd |
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English |
Summary Language |
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Series Editor |
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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 |
1475-7516 |
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:000372467600021 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2590 |
Permanent link to this record |