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Author |
Di Valentino, E.; Gariazzo, S.; Gerbino, M.; Giusarma, E.; Mena, O. |
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Title |
Dark radiation and inflationary freedom after Planck 2015 |
Type |
Journal Article |
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Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
93 |
Issue |
8 |
Pages |
083523 - 28pp |
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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. |
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Address |
[Di Valentino, Eleonora] Inst Astrophys Paris, CNRS, UMR7095, F-75014 Paris, France, Email: valentin@iap.fr |
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Publisher |
Amer Physical Soc |
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English |
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ISSN |
2470-0010 |
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Conference |
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Notes |
WOS:000374960700001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2644 |
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Author |
Di Valentino, E.; Melchiorri, A.; Mena, O. |
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Title |
Can interacting dark energy solve the H-0 tension? |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
96 |
Issue |
4 |
Pages |
043503 - 11pp |
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Abstract |
The answer is yes. We indeed find that interacting dark energy can alleviate the current tension on the value of the Hubble constant H-0 between the cosmic microwave background anisotropies constraints obtained from the Planck satellite and the recent direct measurements reported by Riess et al. 2016. The combination of these two data sets points toward a nonzero dark matter-dark energy coupling. at more than two standard deviations, with xi = -0.26(-0.12)(+0.16) at 95% C.L., i.e. with a moderate evidence for interacting dark energy with an odds ratio of 6:1 respect to a non interacting cosmological constant. However the H-0 tension is better solved when the equation of state of the interacting dark energy component is allowed to freely vary, with a phantomlike equation of state w = -1.185 +/- 0.064 (at 68% C.L.), ruling out the pure cosmological constant case, w = -1, again at more than two standard deviations. When Planck data are combined with external datasets, as BAO, JLA Supernovae Ia luminosity distances, cosmic shear or lensing data, we find perfect consistency with the cosmological constant scenario and no compelling evidence for a dark matter-dark energy coupling. |
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Address |
[Di Valentino, Eleonora] CNRS, Inst Astrophys Paris, UMR7095, F-75014 Paris, France, Email: eleonora.di_valentino@iap.fr; |
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Publisher |
Amer Physical Soc |
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English |
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Series Volume |
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Series Issue |
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ISSN |
2470-0010 |
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Notes |
WOS:000427529900001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3517 |
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Author |
Di Valentino, E.; Giusarma, E.; Lattanzi, M.; Melchiorri, A.; Mena, O. |
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Title |
Axion cold dark matter: Status after Planck and BICEP2 |
Type |
Journal Article |
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Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
90 |
Issue |
4 |
Pages |
043534 - 11pp |
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Keywords |
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Abstract |
We investigate the axion dark matter scenario (ADM), in which axions account for all of the dark matter in the Universe, in light of the most recent cosmological data. In particular, we use the Planck temperature data, complemented by WMAP E-polarization measurements, as well as the recent BICEP2 observations of B-modes. Baryon acoustic oscillation data, including those from the baryon oscillation spectroscopic survey, are also considered in the numerical analyses. We find that, in the minimal ADM scenario and for Delta(QCD) = 200 MeV, the full data set implies that the axion mass m(a) = 82.2 +/- 1.1 μeV [corresponding to the Peccei-Quinn symmetry being broken at a scale f(a) = (7.54 +/- 0.10) x 10(10) GeV], or m(a) = 76.6 +/- 2.6 μeV [f(a) = (8.08 +/- 0.27) x 10(10) GeV] when we allow for a nonstandard effective number of relativistic species N-eff. We also find a 2 sigma preference for N-eff > 3.046. The limit on the sum of neutrino masses is Sigma m(v) < 0.25 eV at 95% C.L. for N-eff = 3.046, or Sigma m(v) < 0.47 eV when N-eff is a free parameter. Considering extended scenarios where either the dark energy equation-of-state parameter w, the tensor spectral index n(t), or the running of the scalar index dn(s)/d ln k is allowed to vary does not change significantly the axion mass-energy density constraints. However, in the case of the full data set exploited here, there is a preference for a nonzero tensor index or scalar running, driven by the different tensor amplitudes implied by the Planck and BICEP2 observations. We also study the effect on our estimates of theoretical uncertainties, in particular the imprecise knowledge of the QCD scale Delta(QCD), in the calculation of the temperature-dependent axion mass. We find that in the simplest ADM scenario the Planck + WP data set implies that the axion mass m(a) = 63.7 +/- 1.2 μeV for Delta(QCD) = 400 MeV. We also comment on the possibility that axions do not make up for all the dark matter, or that the contribution of string-produced axions has been grossly underestimated; in that case, the values that we find for the mass can conservatively be considered as lower limits. Dark matter axions with mass in the 60-80 μeV (corresponding to an axion-photon coupling G(a gamma gamma) similar to 10(-14) GeV-1) range can, in principle, be detected by looking for axion-to-photon conversion occurring inside a tunable microwave cavity permeated by a high-intensity magnetic field, and operating at a frequency nu similar or equal to 15-20 GHz. This is out of the reach of current experiments like the axion dark matter experiment (limited to a maximum frequency of a few GHzs), but is, on the other hand, within the reach of the upcoming axion dark matter experiment-high frequency experiment that will explore the 4-40 GHz frequency range and then be sensitive to axion masses up to similar to 160 μeV. |
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[Di Valentino, Eleonora; Giusarma, Elena; Melchiorri, Alessandro] Univ Roma La Sapienza, Dept Phys, I-00185 Rome, Italy |
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Publisher |
Amer Physical Soc |
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English |
Summary Language |
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Series Editor |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
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Conference |
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Notes |
WOS:000340890100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1893 |
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Author |
Yang, W.Q.; Mena, O.; Pan, S.; Di Valentino, E. |
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Title |
Dark sectors with dynamical coupling |
Type |
Journal Article |
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Year |
2019 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
100 |
Issue |
8 |
Pages |
083509 - 11pp |
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Keywords |
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Abstract |
Coupled dark matter-dark energy scenarios arc modeled via a dimensionless parameter xi, which controls the strength of their interaction. While this coupling is commonly assumed to be constant, there is no underlying physical law or symmetry that forbids a time-dependent xi parameter. The most general and complete interacting scenarios between the two dark sectors should therefore allow for such a possibility, and it is the main purpose of this study to constrain two possible and well-motivated coupled cosmologies by means of the most recent and accurate early- and late-time universe observations. We find that CMB data alone prefer xi(z) > 0 and therefore a smaller amount of dark matter, alleviating some crucial and well-known cosmological data tensions. An objective assessment of the Bayesian evidence for the coupled models explored here shows no particular preference for the presence of a dynamical dark sector coupling. |
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Address |
[Yang, Weiqiang] Liaoning Normal Univ, Dept Phys, Dalian 116029, Peoples R China, Email: d11102004@163.com; |
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Publisher |
Amer Physical Soc |
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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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ISSN |
2470-0010 |
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Conference |
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Notes |
WOS:000489039100003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4166 |
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Author |
Di Valentino, E.; Melchiorri, A.; Mena, O.; Vagnozzi, S. |
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Title |
Interacting dark energy in the early 2020s: A promising solution to the H-0 and cosmic shear tensions |
Type |
Journal Article |
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Year |
2020 |
Publication |
Physics of the Dark Universe |
Abbreviated Journal |
Phys. Dark Universe |
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Volume |
30 |
Issue |
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Pages |
100666 - 12pp |
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Keywords |
Hubble tension; Cosmological parameters; Dark matter; Dark energy; Interacting dark energy |
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Abstract |
We examine interactions between dark matter and dark energy in light of the latest cosmological observations, focusing on a specific model with coupling proportional to the dark energy density. Our data includes Cosmic Microwave Background (CMB) measurements from the Planck 2018 legacy data release, late-time measurements of the expansion history from Baryon Acoustic Oscillations (BAO) and Supernovae Type Ia (SNeIa), galaxy clustering and cosmic shear measurements from the Dark Energy Survey Year 1 results, and the 2019 local distance ladder measurement of the Hubble constant H-0 from the Hubble Space Telescope. Considering Planck data both in combination with BAO or SNeIa data reduces the H-0 tension to a level which could possibly be compatible with a statistical fluctuation. The very same model also significantly reduces the Omega(m) – sigma(8) tension between CMB and cosmic shear measurements. Interactions between the dark sectors of our Universe remain therefore a promising joint solution to these persisting cosmological tensions. |
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Address |
[Di Valentino, Eleonora] Univ Manchester, Jodrell Bank, Ctr Astrophys, Manchester M13 9PL, Lancs, England, Email: eleonora.divalentino@manchester.ac.uk; |
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Publisher |
Elsevier |
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English |
Summary Language |
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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 |
2212-6864 |
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Notes |
WOS:000595300400037 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4646 |
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