Records |
Author |
Diamanti, R.; Giusarma, E.; Mena, O.; Archidiacono, M.; Melchiorri, A. |
Title |
Dark radiation and interacting scenarios |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
87 |
Issue |
6 |
Pages |
063509 - 8pp |
Keywords |
|
Abstract |
An extra dark radiation component can be present in the universe in the form of sterile neutrinos, axions or other very light degrees of freedom which may interact with the dark matter sector. We derive here the cosmological constraints on the dark radiation abundance, on its effective velocity and on its viscosity parameter from current data in dark radiation-dark matter coupled models. The cosmological bounds on the number of extra dark radiation species do not change significantly when considering interacting schemes. We also find that the constraints on the dark radiation effective velocity are degraded by an order of magnitude while the errors on the viscosity parameter are a factor of two larger when considering interacting scenarios. If future Cosmic Microwave Background data are analyzed assuming a noninteracting model but the dark radiation and the dark matter sectors interact in nature, the reconstructed values for the effective velocity and for the viscosity parameter will be shifted from their standard 1/3 expectation, namely c(eff)(2) = 0.34(-0.003)(+0.006) and c(vis)(2) = 0.29(-0.001)(+0.002) at 95% C.L. for the future COrE mission data. |
Address |
[Diamanti, Roberta] Univ Roma Tre, Dept Phys, I-00146 Rome, Italy |
Corporate Author |
|
Thesis |
|
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000315739200004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1349 |
Permanent link to this record |
|
|
|
Author |
Giusarma, E.; Archidiacono, M.; de Putter, R.; Melchiorri, A.; Mena, O. |
Title |
Sterile neutrino models and nonminimal cosmologies |
Type |
Journal Article |
Year |
2012 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
85 |
Issue |
8 |
Pages |
083522 - 9pp |
Keywords |
|
Abstract |
Cosmological measurements are affected by the energy density of massive neutrinos. We extend here a recent analysis of current cosmological data to nonminimal cosmologies. Several possible scenarios are examined: a constant w not equal -1 dark energy equation of state, a nonflat universe, a time-varying dark energy component and coupled dark matter-dark energy universes or modified gravity scenarios. When considering cosmological data only, (3 + 2) massive neutrino models with similar to 0.5 eV sterile species are allowed at 95% confidence level. This scenario has been shown to reconcile reactor, LSND and MiniBooNE positive signals with null results from other searches. Big bang nucleosynthesis bounds could compromise the viability of (3 + 2) models if the two sterile species are fully thermalized states at decoupling. |
Address |
[Giusarma, Elena; de Putter, Roland; Mena, Olga] Univ Valencia CSIC, IFIC, Valencia 46071, Spain |
Corporate Author |
|
Thesis |
|
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000303118100002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
984 |
Permanent link to this record |
|
|
|
Author |
Archidiacono, M.; Lopez-Honorez, L.; Mena, O. |
Title |
Current constraints on early and stressed dark energy models and future 21 cm perspectives |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
90 |
Issue |
12 |
Pages |
123016 - 10pp |
Keywords |
|
Abstract |
Despite the great progress of current cosmological measurements, the nature of the dominant component of the Universe, coined dark energy, is still an open question. Early dark energy is a possible candidate which may also alleviate some fine-tuning issues of the standard paradigm. Using the latest available cosmological data, we find that the 95% C.L. upper bound on the early dark energy density parameter is Tau(eDE) < 0.009. On the other hand, the dark energy component may be a stressed and inhomogeneous fluid. If this is the case, the effective sound speed and the viscosity parameters are unconstrained by current data. Future omniscopelike 21 cm surveys, combined with present cosmic microwave background data, could be able to distinguish between standard quintessence scenarios from other possible models with 2 sigma significance, assuming a non-negligible early dark energy contribution. The precision achieved on the Omega(eDE) parameter from these 21 cm probes could be below O(10%). |
Address |
[Archidiacono, Maria] Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark |
Corporate Author |
|
Thesis |
|
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000347194400007 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2066 |
Permanent link to this record |
|
|
|
Author |
Archidiacono, M.; Giusarma, E.; Hannestad, S.; Mena, O. |
Title |
Cosmic Dark Radiation and Neutrinos |
Type |
Journal Article |
Year |
2013 |
Publication |
Advances in High Energy Physics |
Abbreviated Journal |
Adv. High. Energy Phys. |
Volume |
2013 |
Issue |
|
Pages |
191047 - 14pp |
Keywords |
|
Abstract |
New measurements of the cosmic microwave background (CMB) by the Planck mission have greatly increased our knowledge about the universe. Dark radiation, a weakly interacting component of radiation, is one of the important ingredients in our cosmological model which is testable by Planck and other observational probes. At the moment, the possible existence of dark radiation is an unsolved question. For instance, the discrepancy between the value of the Hubble constant, H-0, inferred from the Planck data and local measurements of H-0 can to some extent be alleviated by enlarging the minimal ACDM model to include additional relativistic degrees of freedom. From a fundamental physics point of view, dark radiation is no less interesting. Indeed, it could well be one of the most accessible windows to physics beyond the standard model, for example, sterile neutrinos. Here, we review the most recent cosmological results including a complete investigation of the dark radiation sector in order to provide an overview of models that are still compatible with new cosmological observations. Furthermore, we update the cosmological constraints on neutrino physics and dark radiation properties focusing on tensions between data sets and degeneracies among parameters that can degrade our information or mimic the existence of extra species. |
Address |
[Archidiacono, Maria; Hannestad, Steen] Univ Aarhus, Dept Phys & Astron, DK-8000 Aarhus C, Denmark, Email: archi@phys.au.dk |
Corporate Author |
|
Thesis |
|
Publisher |
Hindawi Publishing Corporation |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1687-7357 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000327959400001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1660 |
Permanent link to this record |
|
|
|
Author |
Archidiacono, M.; Giusarma, E.; Melchiorri, A.; Mena, O. |
Title |
Neutrino and dark radiation properties in light of recent CMB observations |
Type |
Journal Article |
Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
87 |
Issue |
10 |
Pages |
103519 - 10pp |
Keywords |
|
Abstract |
Recent cosmic microwave background measurements at high multipoles from the South Pole Telescope and from the Atacama Cosmology Telescope seem to disagree in their conclusions for the neutrino and dark radiation properties. In this paper we set new bounds on the dark radiation and neutrino properties in different cosmological scenarios combining the ACT and SPT data with the nine-year data release of the Wilkinson Microwave Anisotropy Probe (WMAP-9), baryon acoustic oscillation data, Hubble Telescope measurements of the Hubble constant, and supernovae Ia luminosity distance data. In the standard three massive neutrino case, the two high multipole probes give similar results if baryon acoustic oscillation data are removed from the analyses and Hubble Telescope measurements are also exploited. A similar result is obtained within a standard cosmology with N-eff massless neutrinos, although in this case the agreement between these two measurements is also improved when considering simultaneously baryon acoustic oscillation data and Hubble Space Telescope measurements. In the N-eff massive neutrino case the two high multipole probes give very different results regardless of the external data sets used in the combined analyses. When considering extended cosmological scenarios with a dark energy equation of state or with a running of the scalar spectral index, the evidence for neutrino masses found for the South Pole Telescope in the three neutrino scenario disappears for all the data combinations explored here. Again, adding Hubble Telescope data seems to improve the agreement between the two high multipole cosmic microwave background measurements considered here. In the case in which a dark radiation background with unknown clustering properties is also considered, SPT data seem to exclude the standard value for the dark radiation viscosity c(vis)(2) = 1/3 at the 2 sigma C.L., finding evidence for massive neutrinos only when combining SPT data with baryon acoustic oscillation measurements. |
Address |
Univ Aarhus, Dept Phys & Astron, DK-8000 Aarhus C, Denmark |
Corporate Author |
|
Thesis |
|
Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1550-7998 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000319254500004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1462 |
Permanent link to this record |