| Records |
| Author |
Di Valentino, E.; Mena, O. |
| Title |
A fake interacting dark energy detection? |
Type |
Journal Article |
| Year |
2021 |
Publication |
Monthly Notices of the Royal Astronomical Society |
Abbreviated Journal  |
Mon. Not. Roy. Astron. Soc. |
| Volume |
500 |
Issue |
1 |
Pages |
L22-L26 |
| Keywords |
cosmic background radiation; cosmological parameters; dark energy |
| Abstract |
Models involving an interaction between the dark matter and the dark energy sectors have been proposed to alleviate the long-standing Hubble constant tension. In this paper, we analyse whether the constraints and potential hints obtained for these interacting models remain unchanged when using simulated Planck data. Interestingly, our simulations indicate that a dangerous fake detection for a non-zero interaction among the dark matter and the dark energy fluids could arise when dealing with current cosmic microwave background (CMB) Planck measurements alone. The very same hypothesis is tested against future CMB observations, finding that only cosmic variance limited polarization experiments, such as PICO or PRISM, could be able to break the existing parameter degeneracies and provide reliable cosmological constraints. This paper underlines the extreme importance of confronting the results arising from data analyses with those obtained with simulations when extracting cosmological limits within exotic cosmological scenarios. |
| Address |
[Di Valentino, Eleonora] Univ Manchester, Jodrell Bank Ctr Astrophys, Sch Phys & Astron, Oxford Rd, Manchester M13 9PL, Lancs, England, Email: eleonora.divalentino@manchester.ac.uk |
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| Publisher |
Oxford Univ Press |
Place of Publication |
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| Language |
English |
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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:000599143200006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
4665 |
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| 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 |
ISBN |
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Expedition |
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Conference |
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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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Thesis |
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| Publisher |
Oxford Univ Press |
Place of Publication |
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| Language |
English |
Summary Language |
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Original Title |
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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: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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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:000770034000012 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
5192 |
| Permanent link to this record |
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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 |
| Corporate Author |
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Thesis |
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| Publisher |
Oxford Univ Press |
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 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 |
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 |
| Permanent link to this record |
