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Author Palomares-Ruiz, S.; Vincent, A.C.; Mena, O. url  doi
openurl 
  Title Spectral analysis of the high-energy IceCube neutrinos Type Journal Article
  Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 91 Issue 10 Pages 103008 - 28pp  
  Keywords  
  Abstract A full energy and flavor-dependent analysis of the three-year high-energy IceCube neutrino events is presented. By means of multidimensional fits, we derive the current preferred values of the high-energy neutrino flavor ratios, the normalization and spectral index of the astrophysical fluxes, and the expected atmospheric background events, including a prompt component. A crucial assumption resides on the choice of the energy interval used for the analyses, which significantly biases the results. When restricting ourselves to the similar to 30 TeV-3 PeV energy range, which contains all the observed IceCube events, we find that the inclusion of the spectral information improves the fit to the canonical flavor composition at Earth, (1: 1: 1)(circle plus), with respect to a single-energy bin analysis. Increasing both the minimum and the maximum deposited energies has dramatic effects on the reconstructed flavor ratios as well as on the spectral index. Imposing a higher threshold of 60 TeV yields a slightly harder spectrum by allowing a larger muon neutrino component, since above this energy most atmospheric tracklike events are effectively removed. Extending the high-energy cutoff to fully cover the Glashow resonance region leads to a softer spectrum and a preference for tau neutrino dominance, as none of the expected electron (anti) neutrino induced showers have been observed so far. The lack of showers at energies above 2 PeV may point to a broken power-law neutrino spectrum. Future data may confirm or falsify whether the recently discovered high-energy neutrino fluxes and the long-standing detected cosmic rays have a common origin.  
  Address [Palomares-Ruiz, Sergio; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000355173100001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2242  
Permanent link to this record
 

 
Author Di Valentino, E.; Gariazzo, S.; Giusarma, E.; Mena, O. url  doi
openurl 
  Title Robustness of cosmological axion mass limits Type Journal Article
  Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 91 Issue 12 Pages 123505 - 12pp  
  Keywords  
  Abstract We present the cosmological bounds on the thermal axion mass in an extended cosmological scenario in which the primordial power spectrum of scalar perturbations differs from the usual power-law shape predicted by the simplest inflationary models. The power spectrum is instead modeled by means of a “piecewise cubic Hermite interpolating polynomial” (PCHIP). When using cosmic microwave background measurements combined with other cosmological data sets, the thermal axion mass constraints are degraded only slightly. The addition of the measurements of sigma(8) and Omega(m) from the 2013 Planck cluster catalog on galaxy number counts relaxes the bounds on the thermal axion mass, mildly favoring a similar to 1 eV axion mass, regardless of the model adopted for the primordial power spectrum. However, in general, such a preference disappears if the sum of the three active neutrino masses is also considered as a free parameter in our numerical analyses, due to the strong correlation between the masses of these two hot thermal relics.  
  Address [Di Valentino, Eleonora] CNRS, UMR 7095, Inst Astrophys Paris, F-75014 Paris, France  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000355623400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2253  
Permanent link to this record
 

 
Author Gariazzo, S.; Lopez-Honorez, L.; Mena, O. url  doi
openurl 
  Title Primordial power spectrum features and f(NL) constraints Type Journal Article
  Year 2015 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 92 Issue 6 Pages 063510 - 12pp  
  Keywords  
  Abstract The simplest models of inflation predict small non-Gaussianities and a featureless power spectrum. However, there exist a large number of well-motivated theoretical scenarios in which large non-Gaussianties could be generated. In general, in these scenarios the primordial power spectrum will deviate from its standard power law shape. We study, in a model-independent manner, the constraints from future large-scale structure surveys on the local non-Gaussianity parameter f(NL) when the standard power law assumption for the primordial power spectrum is relaxed. If the analyses are restricted to the large-scale-dependent bias induced in the linear matter power spectrum by non-Gaussianites, the errors on the f(NL) parameter could be increased by 60% when exploiting data from the future DESI survey, if dealing with only one possible dark matter tracer. In the same context, a nontrivial bias vertical bar delta f(NL)vertical bar similar to 2.5 could be induced if future data are fitted to the wrong primordial power spectrum. Combining all the possible DESI objects slightly ameliorates the problem, as the forecasted errors on f(NL) would be degraded by 40% when relaxing the assumptions concerning the primordial power spectrum shape. Also, the shift on the non-Gaussianity parameter is reduced in this case, vertical bar delta f(NL)vertical bar similar to 1.6. The addition of cosmic microwave background priors ensures robust future f(NL) bounds, as the forecasted errors obtained including these measurements are almost independent on the primordial power spectrum features, and vertical bar delta f(NL)vertical bar similar to 0.2, close to the standard single-field slow-roll paradigm prediction.  
  Address [Gariazzo, Stefano] Univ Turin, Dept Phys, I-10125 Turin, Italy  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000360886300004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2382  
Permanent link to this record
 

 
Author Di Valentino, E.; Giusarma, E.; Mena, O.; Melchiorri, A.; Silk, J. url  doi
openurl 
  Title Cosmological limits on neutrino unknowns versus low redshift priors Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 8 Pages 083527 - 11pp  
  Keywords  
  Abstract Recent cosmic microwave background (CMB) temperature and polarization anisotropy measurements from the Planck mission have significantly improved previous constraints on the neutrino masses as well as the bounds on extended models with massless or massive sterile neutrino states. However, due to parameter degeneracies, additional low redshift priors are mandatory in order to sharpen the CMB neutrino bounds. We explore here the role of different priors on low redshift quantities, such as the Hubble constant, the cluster mass bias, and the reionization optical depth tau. Concerning current priors on the Hubble constant and the cluster mass bias, the bounds on the neutrino parameters may differ appreciably depending on the choices adopted in the analyses. With regard to future improvements in the priors on the reionization optical depth, a value of tau = 0.05 +/- 0.01, motivated by astrophysical estimates of the reionization redshift, would lead to Sigma m(nu) < 0.0926 eV at 90% C.L., when combining the full Planck measurements, baryon acoustic oscillation, and Planck clusters data, thereby opening the window to unravel the neutrino mass hierarchy with existing cosmological probes.  
  Address [Di Valentino, Eleonora; Silk, Joseph] CNRS, Inst Astrophys Paris, UMR7095, F-75014 Paris, France  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000375203600002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2643  
Permanent link to this record
 

 
Author Di Valentino, E.; Gariazzo, S.; Gerbino, M.; Giusarma, E.; Mena, O. url  doi
openurl 
  Title Dark radiation and inflationary freedom after Planck 2015 Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 8 Pages 083523 - 28pp  
  Keywords  
  Abstract The simplest inflationary models predict a primordial power spectrum (PPS) of the curvature fluctuations that can be described by a power-law function that is nearly scale invariant. It has been shown, however, that the low-multipole spectrum of the cosmic microwave background anisotropies may hint at the presence of some features in the shape of the scalar PPS, which could deviate from its canonical power-law form. We study the possible degeneracies of this nonstandard PPS with the active neutrino masses, the effective number of relativistic species, and a sterile neutrino or a thermal axion mass. The limits on these additional parameters are less constraining in a model with a nonstandard PPS when including only the temperature autocorrelation spectrum measurements in the data analyses. The inclusion of the polarization spectra noticeably helps in reducing the degeneracies, leading to results that typically show no deviation from the Lambda CDM model with a standard power-law PPS. These findings are robust against changes in the function describing the noncanonical PPS. Albeit current cosmological measurements seem to prefer the simple power-law PPS description, the statistical significance to rule out other possible parametrizations is still very poor. Future cosmological measurements are crucial to improve the present PPS uncertainties.  
  Address [Di Valentino, Eleonora] Inst Astrophys Paris, CNRS, UMR7095, F-75014 Paris, France, Email: valentin@iap.fr  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000374960700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2644  
Permanent link to this record
 

 
Author Vincent, A.C.; Palomares-Ruiz, S.; Mena, O. url  doi
openurl 
  Title Analysis of the 4-year IceCube high-energy starting events Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 94 Issue 2 Pages 023009 - 18pp  
  Keywords  
  Abstract After four years of data taking, the IceCube neutrino telescope has detected 54 high-energy starting events (HESE, or contained-vertex events) with deposited energies above 20 TeV. They represent the first detection of high-energy extraterrestrial neutrinos and, therefore, the first step in neutrino astronomy. To study the energy, flavor, and isotropy of the astrophysical neutrino flux arriving at Earth, we perform different analyses of two different deposited energy intervals, [10 TeV-10 PeV] and [60 TeV-10 PeV]. We first consider an isotropic unbroken power-law spectrum and constrain its shape, normalization, and flavor composition. Our results are in agreement with the preliminary IceCube results, although we obtain a slightly softer spectrum. We also find that current data are not sensitive to a possible neutrino-antineutrino asymmetry in the astrophysical flux. Then, we show that although a two-component power-law model leads to a slightly better fit, it does not represent a significant improvement with respect to a single power-law flux. Finally, we analyze the possible existence of a north-south asymmetry, hinted at by the combination of the HESE sample with the throughgoing muon data. If we use only HESE data, the scarce statistics from the Northern Hemisphere does not allow us to reach any conclusive answer, which indicates that the HESE sample alone is not driving the potential north-south asymmetry.  
  Address [Vincent, Aaron C.] Univ Durham, Dept Phys, IPPP, Durham DH1 3LE, England, Email: aaron.vincent@durham.ac.uk;  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000381492400002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2783  
Permanent link to this record
 

 
Author Giusarma, E.; Gerbino, M.; Mena, O.; Vagnozzi, S.; Ho, S.; Freese, K. url  doi
openurl 
  Title Improvement of cosmological neutrino mass bounds Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 94 Issue 8 Pages 083522 - 8pp  
  Keywords  
  Abstract The most recent measurements of the temperature and low-multipole polarization anisotropies of the cosmic microwave background from the Planck satellite, when combined with galaxy clustering data from the Baryon Oscillation Spectroscopic Survey in the form of the full shape of the power spectrum, and with baryon acoustic oscillation measurements, provide a 95% confidence level (C.L.) upper bound on the sum of the three active neutrinos Sigma m(nu) < 0.183 eV, among the tightest neutrino mass bounds in the literature, to date, when the same data sets are taken into account. This very same data combination is able to set, at similar to 70% C.L., an upper limit on Sigma m(nu) of 0.0968 eV, a value that approximately corresponds to the minimal mass expected in the inverted neutrino mass hierarchy scenario. If high-multipole polarization data from Planck is also considered, the 95% C.L. upper bound is tightened to Sigma m(nu) < 0.176 eV. Further improvements are obtained by considering recent measurements of the Hubble parameter. These limits are obtained assuming a specific nondegenerate neutrino mass spectrum; they slightly worsen when considering other degenerate neutrino mass schemes. Low-redshift quantities, such as the Hubble constant or the reionization optical depth, play a very important role when setting the neutrino mass constraints. We also comment on the eventual shifts in the cosmological bounds on Sigma m(nu) when possible variations in the former two quantities are addressed.  
  Address [Giusarma, Elena; Ho, Shirley] Carnegie Mellon Univ, Dept Phys, McWilliams Ctr Cosmol, Pittsburgh, PA 15213 USA, Email: egiusarm@andrew.cmu.edu;  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000387120400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2855  
Permanent link to this record
 

 
Author Gariazzo, S.; Mena, O.; Miralles, V.; Ramirez, H.; Boubekeur, L. url  doi
openurl 
  Title Running of featureful primordial power spectra Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 95 Issue 12 Pages 123534 - 7pp  
  Keywords  
  Abstract Current measurements of the temperature and polarization anisotropy power spectra of the cosmic microwave background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm may not be respected in nature. We show that a primordial power spectrum with localized features could in principle give rise to the observed slow-roll anarchy when fitted to a featureless power spectrum. From a model comparison perspective, and assuming that nature has chosen a featureless primordial power spectrum, we find that, while with mock Planck data there is only weak evidence against a model with localized features, upcoming CMB missions may provide compelling evidence against such a nonstandard primordial power spectrum. This evidence could be reinforced if a featureless primordial power spectrum is independently confirmed from bispectrum and/or galaxy clustering measurements.  
  Address [Gariazzo, Stefano; Mena, Olga; Miralles, Victor; Ramirez, Hector] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000404475200004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3186  
Permanent link to this record
 

 
Author Gariazzo, S.; Escudero, M.; Diamanti, R.; Mena, O. url  doi
openurl 
  Title Cosmological searches for a noncold dark matter component Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 96 Issue 4 Pages 043501 - 11pp  
  Keywords  
  Abstract We explore an extended cosmological scenario where the dark matter is an admixture of cold and additional noncold species. The mass and temperature of the noncold dark matter particles are extracted from a number of cosmological measurements. Among others, we consider tomographic weak lensing data and Milky Way dwarf satellite galaxy counts. We also study the potential of these scenarios in alleviating the existing tensions between local measurements and cosmic microwave background ( CMB) estimates of the S-8 parameter, with S-8 = sigma(8)root Omega(m), and of the Hubble constant H-0. In principle, a subdominant, noncold dark matter particle with a mass m(X) similar to keV, could achieve the goals above. However, the preferred ranges for its temperature and its mass are different when extracted from weak lensing observations and from Milky Way dwarf satellite galaxy counts, since these two measurements require suppressions of the matter power spectrum at different scales. Therefore, solving simultaneously the CMB-weak lensing tensions and the small scale crisis in the standard cold dark matter picture via only one noncold dark matter component seems to be challenging.  
  Address [Gariazzo, Stefano; Escudero, Miguel; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Apartado Correos 22085, E-46071 Valencia, Spain  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000406911700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3236  
Permanent link to this record
 

 
Author Lopez-Honorez, L.; Mena, O.; Palomares-Ruiz, S.; Villanueva-Domingo, P. url  doi
openurl 
  Title Warm dark matter and the ionization history of the Universe Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 96 Issue 10 Pages 103539 - 14pp  
  Keywords  
  Abstract In warm dark matter scenarios structure formation is suppressed on small scales with respect to the cold dark matter case, reducing the number of low-mass halos and the fraction of ionized gas at high redshifts and thus, delaying reionization. This has an impact on the ionization history of the Universe and measurements of the optical depth to reionization, of the evolution of the global fraction of ionized gas and of the thermal history of the intergalactic medium, can be used to set constraints on the mass of the dark matter particle. However, the suppression of the fraction of ionized medium in these scenarios can be partly compensated by varying other parameters, as the ionization efficiency or the minimum mass for which halos can host star-forming galaxies. Here we use different data sets regarding the ionization and thermal histories of the Universe and, taking into account the degeneracies from several astrophysical parameters, we obtain a lower bound on the mass of thermal warm dark matter candidates of m(X) > 1.3 keV, or m(s) > 5.5 keV for the case of sterile neutrinos nonresonantly produced in the early Universe, both at 90% confidence level.  
  Address [Lopez-Honorez, Laura] Univ Libre Bruxelles, Serv Phys Theor, CP225,Bld Triomphe, B-1050 Brussels, Belgium  
  Corporate Author Thesis  
  Publisher (up) Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000416238500002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3390  
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