Records |
Author |
Simpson, F.; Jimenez, R.; Pena-Garay, C.; Verde, L. |
Title |
Dark energy from the motions of neutrinos |
Type |
Journal Article |
Year |
2018 |
Publication |
Physics of the Dark Universe |
Abbreviated Journal |
Phys. Dark Universe |
Volume |
20 |
Issue |
|
Pages |
72-77 |
Keywords |
Neutrinos; Dark energy; Interactions in the dark sector |
Abstract |
Ordinarily, a scalar field may only play the role of dark energy if it possesses a potential that is either extraordinarily flat or extremely fine-tuned. Here we demonstrate that these restrictions are lifted when the scalar field undergoes persistent energy exchange with another fluid. In this scenario, the field is prevented from reversing its direction of motion, and instead may come to rest while displaced from the local minimum of its potential. Therefore almost any scalar potential is capable of initiating a prolonged phase of cosmic acceleration. If the rate of energy transfer is modulated via a derivative coupling, the field undergoes a rapid process of freezing, after which the field's equation of state mimicks that of a cosmological constant. We present a physically motivated realisation in the form of a neutrino-majoron coupling, which avoids the dynamical instabilities associated with mass-varying neutrino models. Finally we discuss possible means by which this model could be experimentally verified. |
Address |
[Simpson, Fergus; Jimenez, Raul; Verde, Licia] Univ Barcelona, UB IEEC, ICC, Marti i Franques 1, E-08028 Barcelona 08028, Spain, Email: feigus2@icc.ub.edu; |
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 |
2212-6864 |
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:000433904300009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3599 |
Permanent link to this record |
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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 |
|
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; |
Corporate Author |
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Thesis |
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Publisher |
Elsevier |
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 |
2212-6864 |
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:000595300400037 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4646 |
Permanent link to this record |
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Author |
Yang, W.Q.; Pan, S.; Mena, O.; Di Valentino, E. |
Title |
On the dynamics of a dark sector coupling |
Type |
Journal Article |
Year |
2023 |
Publication |
Journal of High Energy Astrophysics |
Abbreviated Journal |
J. High Energy Astrophys. |
Volume |
40 |
Issue |
|
Pages |
19-40 |
Keywords |
Dark matter; Dark energy; Interacting cosmologies; Cosmological observations |
Abstract |
Interacting dark energy models may play a crucial role in explaining several important observational issues in modern cosmology and also may provide a solution to current cosmological tensions. Since the phenomenology of the dark sector could be extremely rich, one should not restrict the interacting models to have a coupling parameter which is constant in cosmic time, rather allow for its dynamical behaviour, as it is common practice in the literature when dealing with other dark energy properties, as the dark energy equation of state. We present here a compendium of the current cosmological constraints on a large variety of interacting models, investigating scenarios where the coupling parameter of the interaction function and the dark energy equation of state can be either constant or dynamical. For the most general schemes, in which both the coupling parameter of the interaction function and the dark energy equation of state are dynamical, we find 95% CL evidence for a dark energy component at early times and slightly milder evidence for a dynamical dark coupling for the most complete observational data set exploited here, which includes CMB, BAO and Supernova Ia measurements. Interestingly, there are some cases where a dark energy component different from the cosmological constant case at early times together with a coupling different from zero today, can alleviate both the H-0 and S-8 tension for the full dataset combination considered here. Due to the energy exchange among the dark sectors, the current values of the matter energy density and of the clustering parameter sigma(8) are shifted from their ACDM-like values. This fact makes future surveys, especially those focused on weak lensing measurements, unique tools to test the nature and the couplings of the dark energy sector. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons .org /licenses /by /4 .0/). |
Address |
[Yang, Weiqiang] Liaoning Normal Univ, Dept Phys, Dalian 116029, Peoples R China, Email: d11102004@163.com; |
Corporate Author |
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Thesis |
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Publisher |
Elsevier |
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 |
2214-4048 |
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:001089001500001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5761 |
Permanent link to this record |
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Author |
Wang, D. |
Title |
Model-independent traversable wormholes from baryon acoustic oscillations |
Type |
Journal Article |
Year |
2023 |
Publication |
Physics of the Dark Universe |
Abbreviated Journal |
Phys. Dark Universe |
Volume |
42 |
Issue |
|
Pages |
101306 - 8pp |
Keywords |
Traversable wormholes; Dark energy; Baryon acoustic oscillations |
Abstract |
In this paper, we investigate the model-independent traversable wormholes from baryon acoustic oscillations. Firstly, we place the statistical constraints on the average dark energy equation of state Wav by only using BAO data. Subsequently, two specific wormhole solutions are obtained, i.e, the cases of the constant redshift function and a special choice for the shape function. For the first case, we analyze the traversabilities of the wormhole configuration, and for the second case, we find that one can construct theoretically a traversable wormhole with infinitesimal amounts of average null energy condition violating phantom fluid. Furthermore, we perform the stability analysis for the first case, and find that the stable equilibrium configurations may increase for increasing values of the throat radius of the wormhole in the cases of a positive and a negative surface energy density. It is worth noting that the obtained wormhole solutions are static and spherically symmetrical metric, and that we assume Wav to be a constant between different redshifts when placing constraints, hence, these wormhole solutions can be interpreted as stable and static phantom wormholes configurations at some certain redshift which lies in the range [0.32, 2.34]. |
Address |
[Wang, Deng] Univ Valencia, Inst Fis Corpuscular, CSIC, E-46980 Paterna, Spain, Email: cstar@nao.cas.cn |
Corporate Author |
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Thesis |
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Publisher |
Elsevier |
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 |
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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:001122744700001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5853 |
Permanent link to this record |
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Author |
Reichardt, C.L.; de Putter, R.; Zahn, O.; Hou, Z. |
Title |
New limits on early dark energy from the South Pole telescope |
Type |
Journal Article |
Year |
2012 |
Publication |
Astrophysical Journal Letters |
Abbreviated Journal |
Astrophys. J. Lett. |
Volume |
749 |
Issue |
1 |
Pages |
L9 - 5pp |
Keywords |
cosmic background radiation; dark energy; early universe |
Abstract |
We present new limits on early dark energy (EDE) from the cosmic microwave background (CMB) using data from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite on large angular scales and South Pole Telescope on small angular scales. We find a strong upper limit on the EDE density of Omega(e) < 0.018 at 95% confidence, a factor of three improvement over WMAP data alone. We show that adding lower-redshift probes of the expansion rate to the CMB data improves constraints on the dark energy equation of state, but not the EDE density. We also explain how small-scale CMB temperature anisotropy constrains EDE. |
Address |
[Reichardt, C. L.; Zahn, O.] Univ Calif Berkeley, Dept Phys, Berkeley Ctr Cosmol Phys, Berkeley, CA 94720 USA, Email: cr@bolo.berkeley.edu |
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 |
2041-8205 |
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:000302143100009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
962 |
Permanent link to this record |