Records |
Author |
Palomares-Ruiz, S.; Vincent, A.C.; Mena, O. |
Title |
Spectral analysis of the high-energy IceCube neutrinos |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal ![sorted by Abbreviated Journal field, descending order (down)](img/sort_desc.gif) |
Phys. Rev. D |
Volume |
91 |
Issue |
10 |
Pages |
103008 - 28pp |
Keywords |
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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 |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000355173100001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2242 |
Permanent link to this record |
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Author |
Di Valentino, E.; Gariazzo, S.; Giusarma, E.; Mena, O. |
Title |
Robustness of cosmological axion mass limits |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal ![sorted by Abbreviated Journal field, descending order (down)](img/sort_desc.gif) |
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 |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
1550-7998 |
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:000355623400003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2253 |
Permanent link to this record |
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Author |
Gariazzo, S.; Lopez-Honorez, L.; Mena, O. |
Title |
Primordial power spectrum features and f(NL) constraints |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal ![sorted by Abbreviated Journal field, descending order (down)](img/sort_desc.gif) |
Phys. Rev. D |
Volume |
92 |
Issue |
6 |
Pages |
063510 - 12pp |
Keywords |
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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 |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
1550-7998 |
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:000360886300004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2382 |
Permanent link to this record |
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Author |
Di Valentino, E.; Giusarma, E.; Mena, O.; Melchiorri, A.; Silk, J. |
Title |
Cosmological limits on neutrino unknowns versus low redshift priors |
Type |
Journal Article |
Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal ![sorted by Abbreviated Journal field, descending order (down)](img/sort_desc.gif) |
Phys. Rev. D |
Volume |
93 |
Issue |
8 |
Pages |
083527 - 11pp |
Keywords |
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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 |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
2470-0010 |
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:000375203600002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2643 |
Permanent link to this record |
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Author |
Di Valentino, E.; Gariazzo, S.; Gerbino, M.; Giusarma, E.; Mena, O. |
Title |
Dark radiation and inflationary freedom after Planck 2015 |
Type |
Journal Article |
Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal ![sorted by Abbreviated Journal field, descending order (down)](img/sort_desc.gif) |
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 |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
|
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 |
|
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 |