| Records |
| Author |
Di Valentino, E.; Melchiorri, A.; Mena, O.; Pan, S.; Yang, W.Q. |
| Title |
Interacting dark energy in a closed universe |
Type |
Journal Article |
| Year |
2021 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal  |
Mon. Not. Roy. Astron. Soc. |
| Volume |
502 |
Issue |
1 |
Pages |
L23-L28 |
| Keywords |
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| Abstract |
Recent measurements of the Cosmic Microwave Anisotropies power spectra measured by the Planck satellite show a preference for a closed universe at more than 99 per cent confidence level (CL). Such a scenario is however in disagreement with several low redshift observables, including luminosity distances of Type Ia supernovae. Here we show that interacting dark energy (IDE) models can ease the discrepancies between Planck and supernovae Ia data in a closed Universe, leading to a preference for both a coupling and a curvature different from zero above the 99 per cent CL. Therefore IDE cosmologies remain as very appealing scenarios, as they can provide the solution to a number of observational tensions in different fiducial cosmologies. The results presented here strongly favour broader analyses of cosmological data, and suggest that relaxing the usual flatness and vacuum energy assumptions can lead to a much better agreement among theory and observations. |
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| ISSN |
0035-8711 |
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| Notes |
WOS:000662142100005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4879 |
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| Author |
Giare, W.; Di Valentino, E.; Melchiorri, A.; Mena, O. |
| Title |
New cosmological bounds on hot relics: axions and neutrinos |
Type |
Journal Article |
| Year |
2021 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
| Volume |
505 |
Issue |
2 |
Pages |
2703-2711 |
| Keywords |
cosmic background radiation; cosmological parameters; dark matter; early Universe; cosmology: observations |
| Abstract |
Axions, if realized in nature, can be copiously produced in the early universe via thermal processes, contributing to the mass-energy density of thermal hot relics. In light of the most recent cosmological observations, we analyse two different thermal processes within a realistic mixed hot dark matter scenario which includes also massive neutrinos. Considering the axion-gluon thermalization channel, we derive our most constraining bounds on the hot relic masses m(a) < 7.46 eV and Sigma m(nu) < 0.114 eV both at 95 percent CL; while studying the axion-pion scattering, without assuming any specific model for the axion-pion interactions, and remaining in the range of validity of the chiral perturbation theory, our most constraining bounds are improved to m(a) < 0.91 eV and Sigma m(nu) < 0.105 eV, both at 95 percent CL. Interestingly, in both cases, the total neutrino mass lies very close to the inverted neutrino mass ordering prediction. If future terrestrial double beta decay and/or long-baseline neutrino experiments find that the nature mass ordering is the inverted one, this could rule out a wide region in the currently allowed thermal axion window. Our results therefore, strongly support multi messenger searches of axions and neutrino properties, together with joint analyses of their expected sensitivities. |
| Address |
[Giare, William; Melchiorri, Alessandro] Univ Roma La Sapienza, Phys Dept, Ple Aldo Moro 2, I-00185 Rome, Italy, Email: william.giare@gmail.com |
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| Publisher |
Oxford Univ Press |
Place of Publication |
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| Language |
English |
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0035-8711 |
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Conference |
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| Notes |
WOS:000672803400085 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4912 |
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| Author |
Giare, W.; Renzi, F.; Melchiorri, A.; Mena, O.; Di Valentino, E. |
| Title |
Cosmological forecasts on thermal axions, relic neutrinos, and light elements |
Type |
Journal Article |
| Year |
2022 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
| Volume |
511 |
Issue |
1 |
Pages |
1373-1382 |
| Keywords |
cosmic background radiation; cosmological parameters; dark matter; early Universe; cosmology: observations |
| Abstract |
One of the targets of future cosmic microwave background (CMB) and baryon acoustic oscillation measurements is to improve the current accuracy in the neutrino sector and reach a much better sensitivity on extra dark radiation in the early Universe. In this paper, we study how these improvements can be translated into constraining power for well-motivated extensions of the standard model of elementary particles that involve axions thermalized before the quantum chromodynamics (QCD) phase transition by scatterings with gluons. Assuming a fiducial Lambda cold dark matter cosmological model, we simulate future data for Stage-IV CMB-like and Dark Energy Spectroscopic Instrument (DESI)-like surveys and analyse a mixed scenario of axion and neutrino hot dark matter. We further account also for the effects of these QCD axions on the light element abundances predicted by big bang nucleosynthesis. The most constraining forecasted limits on the hot relic masses are m(a) less than or similar to 0.92 eV and n-ary sumation m(nu) less than or similar to 0.12 eV at 95 per cent Confidence Level, showing that future cosmic observations can substantially improve the current bounds, supporting multimessenger analyses of axion, neutrino, and primordial light element properties. |
| Address |
[Giare, William; Melchiorri, Alessandro] Univ Roma La Sapienza, Phys Dept, Ple Aldo Moro 2, I-00185 Rome, Italy, Email: william.giare@gmail.com |
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| Publisher |
Oxford Univ Press |
Place of Publication |
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| Language |
English |
Summary Language |
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Series Issue |
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Edition |
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| ISSN |
0035-8711 |
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:000770034000012 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5192 |
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| Author |
Giare, W.; Renzi, F.; Mena, O.; Di Valentino, E.; Melchiorri, A. |
| Title |
Is the Harrison-Zel'dovich spectrum coming back? ACT preference for n(s) similar to 1 and its discordance with Planck |
Type |
Journal Article |
| Year |
2023 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal |
Mon. Not. Roy. Astron. Soc. |
| Volume |
521 |
Issue |
2 |
Pages |
2911-2918 |
| Keywords |
cosmological parameters; inflation; cosmology: observations; cosmology: theory |
| Abstract |
The Data Release 4 of the Atacama Cosmology Telescope (ACT) shows an agreement with an Harrison-Zel'dovich primordial spectrum (n(s) = 1.009 +/- 0.015), introducing a tension with a significance of 99.3 per cent Confidence Level (CL) with the results from the Planck satellite. The discrepancy on the value of the scalar spectral index is neither alleviated with the addition of large scale structure information nor with the low multipole polarization data. We discuss possible avenues to alleviate the tension relying on either neglecting polarization measurements from ACT or in extending different sectors of the theory. |
| Address |
[Giare, William] Ctr Nazl INFN Studi Avanzati, Galileo Galileo Inst Theoret Phys, Largo Enr Fermi 2, I-50125 Florence, Italy, Email: william.giare@gmail.com |
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| Publisher |
Oxford Univ Press |
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| Language |
English |
Summary Language |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0035-8711 |
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:000957248500013 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5510 |
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| Author |
Di Valentino, E.; Melchiorri, A.; Mena, O.; Vagnozzi, S. |
| Title |
Interacting dark energy in the early 2020s: A promising solution to the H-0 and cosmic shear tensions |
Type |
Journal Article |
| Year |
2020 |
Publication |
Physics of the Dark Universe |
Abbreviated Journal |
Phys. Dark Universe |
| Volume |
30 |
Issue |
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Pages |
100666 - 12pp |
| Keywords |
Hubble tension; Cosmological parameters; Dark matter; Dark energy; Interacting dark energy |
| 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. |
| 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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Elsevier |
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English |
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2212-6864 |
ISBN |
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Expedition |
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Conference |
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| Notes |
WOS:000595300400037 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4646 |
| Permanent link to this record |
