| Records |
| 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 |
Phys. Rev. D |
| Volume |
91 |
Issue |
12 |
Pages |
123505 - 12pp |
| Keywords |
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| 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 |
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| Author |
Vincent, A.C.; Fernandez Martinez, E.; Hernandez, P.; Mena, O.; Lattanzi, M. |
| Title |
Revisiting cosmological bounds on sterile neutrinos |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
006 - 23pp |
| Keywords |
particle physics – cosmology connection; cosmological neutrinos; cosmology of theories beyond the SM |
| Abstract |
We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter R-CMB and the sound horizon r(s) from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin(2) theta less than or similar to 0.026(m(s)/eV)(-2). |
| Address |
[Vincent, Aaron C.] Univ Durham, Dept Phys, IPPP, Durham DH1 3LE, England, Email: aaron.vincent@durham.ac.uk; |
| 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 |
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:000355742500007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2261 |
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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 |
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 |
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| Author |
Escudero, M.; Mena, O.; Vincent, A.C.; Wilkinson, R.J.; Boehm, C. |
| Title |
Exploring dark matter microphysics with galaxy surveys |
Type |
Journal Article |
| Year |
2015 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
09 |
Issue |
9 |
Pages |
034 - 16pp |
| Keywords |
dark matter theory; galaxy surveys; cosmological parameters from CMBR |
| Abstract |
We use present cosmological observations and forecasts of future experiments to illustrate the power of large-scale structure (LSS) surveys in probing dark matter (DM) microphysics and unveiling potential deviations from the standard ACDM scenario. To quantify this statement, we focus on an extension of ACDM with DM-neutrino scattering, which leaves a distinctive imprint on the angular and matter power spectra. After finding that future CMB experiments (such as COrE+) will not significantly improve the constraints set by the Planck satellite, we show that the next generation of galaxy clustering surveys (such as DESI) could play a leading role in constraining alternative cosmologies and even have the potential to make a discovery. Typically we find that DESI would be an order of magnitude more sensitive to DM interactions than Planck, thus probing effects that until now have only been accessible via N-body simulations. |
| Address |
[Escudero, Miguel; Mena, Olga] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain, Email: miguel.Escudero@uv.s; |
| 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 |
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:000365690000034 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2480 |
| Permanent link to this record |
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| Author |
Di Valentino, E.; Giusarma, E.; Lattanzi, M.; Mena, O.; Melchiorri, A.; Silk, J. |
| Title |
Cosmological axion and neutrino mass constraints from Planck 2015 temperature and polarization data |
Type |
Journal Article |
| Year |
2016 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
| Volume |
752 |
Issue |
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Pages |
182-185 |
| Keywords |
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| Abstract |
Axions currently provide the most compelling solution to the strong CP problem. These particles may be copiously produced in the early universe, including via thermal processes. Therefore, relic axions constitute a hot dark matter component and their masses are strongly degenerate with those of the three active neutrinos, as they leave identical signatures in the different cosmological observables. In addition, thermal axions, while still relativistic states, also contribute to the relativistic degrees of freedom, parameterized via N-eff. We present the cosmological bounds on the relic axion and neutrino masses, exploiting the full Planck mission data, which include polarization measurements. In the mixed hot dark matter scenario explored here, we find the tightest and more robust constraint to date on the sum of the three active neutrino masses, Sigma m nu < 0.136eV at 95% CL, as it is obtained in the very well-known linear perturbation regime. The Planck Sunyaev-Zeldovich cluster number count data further tightens this bound, providing a 95% CL upper limit of Sigma m nu < 0.126 eV in this very same mixed hot dark matter model, a value which is very close to the expectations in the inverted hierarchical neutrino mass scenario. Using this same combination of data sets we find the most stringent bound to date on the thermal axion mass, m(a) < 0.529 eV at 95% CL. |
| Address |
[Di Valentino, Eleonora; Silk, Joseph] CNRS, UMR7095, Inst Astrophys Paris, F-75014 Paris, France, Email: elena.giusarma@roma1.infn.it |
| Corporate Author |
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Thesis |
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| Publisher |
Elsevier Science Bv |
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 |
0370-2693 |
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:000368026000026 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2524 |
| Permanent link to this record |
